Merge pull request #10844 from vrothberg/vendor-common

vendor containers/common@main

7 files changed, 1911 insertions, 0 deletions

diff --git a/vendor/github.com/mitchellh/mapstructure/CHANGELOG.md b/vendor/github.com/mitchellh/mapstructure/CHANGELOG.md
new file mode 100644
index 000000000..1955f2878
--- /dev/null
+++ b/vendor/github.com/mitchellh/mapstructure/CHANGELOG.md
@@ -0,0 +1,73 @@
+## unreleased
+
+* Fix regression where `*time.Time` value would be set to empty and not be sent 
+  to decode hooks properly [GH-232]
+
+## 1.4.0
+
+* A new decode hook type `DecodeHookFuncValue` has been added that has
+  access to the full values. [GH-183]
+* Squash is now supported with embedded fields that are struct pointers [GH-205]
+* Empty strings will convert to 0 for all numeric types when weakly decoding [GH-206]
+
+## 1.3.3
+
+* Decoding maps from maps creates a settable value for decode hooks [GH-203]
+
+## 1.3.2
+
+* Decode into interface type with a struct value is supported [GH-187]
+
+## 1.3.1
+
+* Squash should only squash embedded structs. [GH-194]
+
+## 1.3.0
+
+* Added `",omitempty"` support. This will ignore zero values in the source
+  structure when encoding. [GH-145]
+
+## 1.2.3
+
+* Fix duplicate entries in Keys list with pointer values. [GH-185]
+
+## 1.2.2
+
+* Do not add unsettable (unexported) values to the unused metadata key
+  or "remain" value. [GH-150]
+
+## 1.2.1
+
+* Go modules checksum mismatch fix
+
+## 1.2.0
+
+* Added support to capture unused values in a field using the `",remain"` value
+  in the mapstructure tag. There is an example to showcase usage.
+* Added `DecoderConfig` option to always squash embedded structs
+* `json.Number` can decode into `uint` types
+* Empty slices are preserved and not replaced with nil slices
+* Fix panic that can occur in when decoding a map into a nil slice of structs
+* Improved package documentation for godoc
+
+## 1.1.2
+
+* Fix error when decode hook decodes interface implementation into interface
+  type. [GH-140]
+
+## 1.1.1
+
+* Fix panic that can happen in `decodePtr`
+
+## 1.1.0
+
+* Added `StringToIPHookFunc` to convert `string` to `net.IP` and `net.IPNet` [GH-133]
+* Support struct to struct decoding [GH-137]
+* If source map value is nil, then destination map value is nil (instead of empty)
+* If source slice value is nil, then destination slice value is nil (instead of empty)
+* If source pointer is nil, then destination pointer is set to nil (instead of
+  allocated zero value of type)
+
+## 1.0.0
+
+* Initial tagged stable release.
diff --git a/vendor/github.com/mitchellh/mapstructure/LICENSE b/vendor/github.com/mitchellh/mapstructure/LICENSE
new file mode 100644
index 000000000..f9c841a51
--- /dev/null
+++ b/vendor/github.com/mitchellh/mapstructure/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2013 Mitchell Hashimoto
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/vendor/github.com/mitchellh/mapstructure/README.md b/vendor/github.com/mitchellh/mapstructure/README.md
new file mode 100644
index 000000000..0018dc7d9
--- /dev/null
+++ b/vendor/github.com/mitchellh/mapstructure/README.md
@@ -0,0 +1,46 @@
+# mapstructure [![Godoc](https://godoc.org/github.com/mitchellh/mapstructure?status.svg)](https://godoc.org/github.com/mitchellh/mapstructure)
+
+mapstructure is a Go library for decoding generic map values to structures
+and vice versa, while providing helpful error handling.
+
+This library is most useful when decoding values from some data stream (JSON,
+Gob, etc.) where you don't _quite_ know the structure of the underlying data
+until you read a part of it. You can therefore read a `map[string]interface{}`
+and use this library to decode it into the proper underlying native Go
+structure.
+
+## Installation
+
+Standard `go get`:
+
+```
+$ go get github.com/mitchellh/mapstructure
+```
+
+## Usage & Example
+
+For usage and examples see the [Godoc](http://godoc.org/github.com/mitchellh/mapstructure).
+
+The `Decode` function has examples associated with it there.
+
+## But Why?!
+
+Go offers fantastic standard libraries for decoding formats such as JSON.
+The standard method is to have a struct pre-created, and populate that struct
+from the bytes of the encoded format. This is great, but the problem is if
+you have configuration or an encoding that changes slightly depending on
+specific fields. For example, consider this JSON:
+
+```json
+{
+  "type": "person",
+  "name": "Mitchell"
+}
+```
+
+Perhaps we can't populate a specific structure without first reading
+the "type" field from the JSON. We could always do two passes over the
+decoding of the JSON (reading the "type" first, and the rest later).
+However, it is much simpler to just decode this into a `map[string]interface{}`
+structure, read the "type" key, then use something like this library
+to decode it into the proper structure.
diff --git a/vendor/github.com/mitchellh/mapstructure/decode_hooks.go b/vendor/github.com/mitchellh/mapstructure/decode_hooks.go
new file mode 100644
index 000000000..92e6f76ff
--- /dev/null
+++ b/vendor/github.com/mitchellh/mapstructure/decode_hooks.go
@@ -0,0 +1,256 @@
+package mapstructure
+
+import (
+	"encoding"
+	"errors"
+	"fmt"
+	"net"
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// typedDecodeHook takes a raw DecodeHookFunc (an interface{}) and turns
+// it into the proper DecodeHookFunc type, such as DecodeHookFuncType.
+func typedDecodeHook(h DecodeHookFunc) DecodeHookFunc {
+	// Create variables here so we can reference them with the reflect pkg
+	var f1 DecodeHookFuncType
+	var f2 DecodeHookFuncKind
+	var f3 DecodeHookFuncValue
+
+	// Fill in the variables into this interface and the rest is done
+	// automatically using the reflect package.
+	potential := []interface{}{f1, f2, f3}
+
+	v := reflect.ValueOf(h)
+	vt := v.Type()
+	for _, raw := range potential {
+		pt := reflect.ValueOf(raw).Type()
+		if vt.ConvertibleTo(pt) {
+			return v.Convert(pt).Interface()
+		}
+	}
+
+	return nil
+}
+
+// DecodeHookExec executes the given decode hook. This should be used
+// since it'll naturally degrade to the older backwards compatible DecodeHookFunc
+// that took reflect.Kind instead of reflect.Type.
+func DecodeHookExec(
+	raw DecodeHookFunc,
+	from reflect.Value, to reflect.Value) (interface{}, error) {
+
+	switch f := typedDecodeHook(raw).(type) {
+	case DecodeHookFuncType:
+		return f(from.Type(), to.Type(), from.Interface())
+	case DecodeHookFuncKind:
+		return f(from.Kind(), to.Kind(), from.Interface())
+	case DecodeHookFuncValue:
+		return f(from, to)
+	default:
+		return nil, errors.New("invalid decode hook signature")
+	}
+}
+
+// ComposeDecodeHookFunc creates a single DecodeHookFunc that
+// automatically composes multiple DecodeHookFuncs.
+//
+// The composed funcs are called in order, with the result of the
+// previous transformation.
+func ComposeDecodeHookFunc(fs ...DecodeHookFunc) DecodeHookFunc {
+	return func(f reflect.Value, t reflect.Value) (interface{}, error) {
+		var err error
+		var data interface{}
+		newFrom := f
+		for _, f1 := range fs {
+			data, err = DecodeHookExec(f1, newFrom, t)
+			if err != nil {
+				return nil, err
+			}
+			newFrom = reflect.ValueOf(data)
+		}
+
+		return data, nil
+	}
+}
+
+// StringToSliceHookFunc returns a DecodeHookFunc that converts
+// string to []string by splitting on the given sep.
+func StringToSliceHookFunc(sep string) DecodeHookFunc {
+	return func(
+		f reflect.Kind,
+		t reflect.Kind,
+		data interface{}) (interface{}, error) {
+		if f != reflect.String || t != reflect.Slice {
+			return data, nil
+		}
+
+		raw := data.(string)
+		if raw == "" {
+			return []string{}, nil
+		}
+
+		return strings.Split(raw, sep), nil
+	}
+}
+
+// StringToTimeDurationHookFunc returns a DecodeHookFunc that converts
+// strings to time.Duration.
+func StringToTimeDurationHookFunc() DecodeHookFunc {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{}) (interface{}, error) {
+		if f.Kind() != reflect.String {
+			return data, nil
+		}
+		if t != reflect.TypeOf(time.Duration(5)) {
+			return data, nil
+		}
+
+		// Convert it by parsing
+		return time.ParseDuration(data.(string))
+	}
+}
+
+// StringToIPHookFunc returns a DecodeHookFunc that converts
+// strings to net.IP
+func StringToIPHookFunc() DecodeHookFunc {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{}) (interface{}, error) {
+		if f.Kind() != reflect.String {
+			return data, nil
+		}
+		if t != reflect.TypeOf(net.IP{}) {
+			return data, nil
+		}
+
+		// Convert it by parsing
+		ip := net.ParseIP(data.(string))
+		if ip == nil {
+			return net.IP{}, fmt.Errorf("failed parsing ip %v", data)
+		}
+
+		return ip, nil
+	}
+}
+
+// StringToIPNetHookFunc returns a DecodeHookFunc that converts
+// strings to net.IPNet
+func StringToIPNetHookFunc() DecodeHookFunc {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{}) (interface{}, error) {
+		if f.Kind() != reflect.String {
+			return data, nil
+		}
+		if t != reflect.TypeOf(net.IPNet{}) {
+			return data, nil
+		}
+
+		// Convert it by parsing
+		_, net, err := net.ParseCIDR(data.(string))
+		return net, err
+	}
+}
+
+// StringToTimeHookFunc returns a DecodeHookFunc that converts
+// strings to time.Time.
+func StringToTimeHookFunc(layout string) DecodeHookFunc {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{}) (interface{}, error) {
+		if f.Kind() != reflect.String {
+			return data, nil
+		}
+		if t != reflect.TypeOf(time.Time{}) {
+			return data, nil
+		}
+
+		// Convert it by parsing
+		return time.Parse(layout, data.(string))
+	}
+}
+
+// WeaklyTypedHook is a DecodeHookFunc which adds support for weak typing to
+// the decoder.
+//
+// Note that this is significantly different from the WeaklyTypedInput option
+// of the DecoderConfig.
+func WeaklyTypedHook(
+	f reflect.Kind,
+	t reflect.Kind,
+	data interface{}) (interface{}, error) {
+	dataVal := reflect.ValueOf(data)
+	switch t {
+	case reflect.String:
+		switch f {
+		case reflect.Bool:
+			if dataVal.Bool() {
+				return "1", nil
+			}
+			return "0", nil
+		case reflect.Float32:
+			return strconv.FormatFloat(dataVal.Float(), 'f', -1, 64), nil
+		case reflect.Int:
+			return strconv.FormatInt(dataVal.Int(), 10), nil
+		case reflect.Slice:
+			dataType := dataVal.Type()
+			elemKind := dataType.Elem().Kind()
+			if elemKind == reflect.Uint8 {
+				return string(dataVal.Interface().([]uint8)), nil
+			}
+		case reflect.Uint:
+			return strconv.FormatUint(dataVal.Uint(), 10), nil
+		}
+	}
+
+	return data, nil
+}
+
+func RecursiveStructToMapHookFunc() DecodeHookFunc {
+	return func(f reflect.Value, t reflect.Value) (interface{}, error) {
+		if f.Kind() != reflect.Struct {
+			return f.Interface(), nil
+		}
+
+		var i interface{} = struct{}{}
+		if t.Type() != reflect.TypeOf(&i).Elem() {
+			return f.Interface(), nil
+		}
+
+		m := make(map[string]interface{})
+		t.Set(reflect.ValueOf(m))
+
+		return f.Interface(), nil
+	}
+}
+
+// TextUnmarshallerHookFunc returns a DecodeHookFunc that applies
+// strings to the UnmarshalText function, when the target type
+// implements the encoding.TextUnmarshaler interface
+func TextUnmarshallerHookFunc() DecodeHookFuncType {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{}) (interface{}, error) {
+		if f.Kind() != reflect.String {
+			return data, nil
+		}
+		result := reflect.New(t).Interface()
+		unmarshaller, ok := result.(encoding.TextUnmarshaler)
+		if !ok {
+			return data, nil
+		}
+		if err := unmarshaller.UnmarshalText([]byte(data.(string))); err != nil {
+			return nil, err
+		}
+		return result, nil
+	}
+}
diff --git a/vendor/github.com/mitchellh/mapstructure/error.go b/vendor/github.com/mitchellh/mapstructure/error.go
new file mode 100644
index 000000000..47a99e5af
--- /dev/null
+++ b/vendor/github.com/mitchellh/mapstructure/error.go
@@ -0,0 +1,50 @@
+package mapstructure
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// Error implements the error interface and can represents multiple
+// errors that occur in the course of a single decode.
+type Error struct {
+	Errors []string
+}
+
+func (e *Error) Error() string {
+	points := make([]string, len(e.Errors))
+	for i, err := range e.Errors {
+		points[i] = fmt.Sprintf("* %s", err)
+	}
+
+	sort.Strings(points)
+	return fmt.Sprintf(
+		"%d error(s) decoding:\n\n%s",
+		len(e.Errors), strings.Join(points, "\n"))
+}
+
+// WrappedErrors implements the errwrap.Wrapper interface to make this
+// return value more useful with the errwrap and go-multierror libraries.
+func (e *Error) WrappedErrors() []error {
+	if e == nil {
+		return nil
+	}
+
+	result := make([]error, len(e.Errors))
+	for i, e := range e.Errors {
+		result[i] = errors.New(e)
+	}
+
+	return result
+}
+
+func appendErrors(errors []string, err error) []string {
+	switch e := err.(type) {
+	case *Error:
+		return append(errors, e.Errors...)
+	default:
+		return append(errors, e.Error())
+	}
+}
diff --git a/vendor/github.com/mitchellh/mapstructure/go.mod b/vendor/github.com/mitchellh/mapstructure/go.mod
new file mode 100644
index 000000000..a03ae9730
--- /dev/null
+++ b/vendor/github.com/mitchellh/mapstructure/go.mod
@@ -0,0 +1,3 @@
+module github.com/mitchellh/mapstructure
+
+go 1.14
diff --git a/vendor/github.com/mitchellh/mapstructure/mapstructure.go b/vendor/github.com/mitchellh/mapstructure/mapstructure.go
new file mode 100644
index 000000000..3643901f5
--- /dev/null
+++ b/vendor/github.com/mitchellh/mapstructure/mapstructure.go
@@ -0,0 +1,1462 @@
+// Package mapstructure exposes functionality to convert one arbitrary
+// Go type into another, typically to convert a map[string]interface{}
+// into a native Go structure.
+//
+// The Go structure can be arbitrarily complex, containing slices,
+// other structs, etc. and the decoder will properly decode nested
+// maps and so on into the proper structures in the native Go struct.
+// See the examples to see what the decoder is capable of.
+//
+// The simplest function to start with is Decode.
+//
+// Field Tags
+//
+// When decoding to a struct, mapstructure will use the field name by
+// default to perform the mapping. For example, if a struct has a field
+// "Username" then mapstructure will look for a key in the source value
+// of "username" (case insensitive).
+//
+//     type User struct {
+//         Username string
+//     }
+//
+// You can change the behavior of mapstructure by using struct tags.
+// The default struct tag that mapstructure looks for is "mapstructure"
+// but you can customize it using DecoderConfig.
+//
+// Renaming Fields
+//
+// To rename the key that mapstructure looks for, use the "mapstructure"
+// tag and set a value directly. For example, to change the "username" example
+// above to "user":
+//
+//     type User struct {
+//         Username string `mapstructure:"user"`
+//     }
+//
+// Embedded Structs and Squashing
+//
+// Embedded structs are treated as if they're another field with that name.
+// By default, the two structs below are equivalent when decoding with
+// mapstructure:
+//
+//     type Person struct {
+//         Name string
+//     }
+//
+//     type Friend struct {
+//         Person
+//     }
+//
+//     type Friend struct {
+//         Person Person
+//     }
+//
+// This would require an input that looks like below:
+//
+//     map[string]interface{}{
+//         "person": map[string]interface{}{"name": "alice"},
+//     }
+//
+// If your "person" value is NOT nested, then you can append ",squash" to
+// your tag value and mapstructure will treat it as if the embedded struct
+// were part of the struct directly. Example:
+//
+//     type Friend struct {
+//         Person `mapstructure:",squash"`
+//     }
+//
+// Now the following input would be accepted:
+//
+//     map[string]interface{}{
+//         "name": "alice",
+//     }
+//
+// When decoding from a struct to a map, the squash tag squashes the struct
+// fields into a single map. Using the example structs from above:
+//
+//     Friend{Person: Person{Name: "alice"}}
+//
+// Will be decoded into a map:
+//
+//     map[string]interface{}{
+//         "name": "alice",
+//     }
+//
+// DecoderConfig has a field that changes the behavior of mapstructure
+// to always squash embedded structs.
+//
+// Remainder Values
+//
+// If there are any unmapped keys in the source value, mapstructure by
+// default will silently ignore them. You can error by setting ErrorUnused
+// in DecoderConfig. If you're using Metadata you can also maintain a slice
+// of the unused keys.
+//
+// You can also use the ",remain" suffix on your tag to collect all unused
+// values in a map. The field with this tag MUST be a map type and should
+// probably be a "map[string]interface{}" or "map[interface{}]interface{}".
+// See example below:
+//
+//     type Friend struct {
+//         Name  string
+//         Other map[string]interface{} `mapstructure:",remain"`
+//     }
+//
+// Given the input below, Other would be populated with the other
+// values that weren't used (everything but "name"):
+//
+//     map[string]interface{}{
+//         "name":    "bob",
+//         "address": "123 Maple St.",
+//     }
+//
+// Omit Empty Values
+//
+// When decoding from a struct to any other value, you may use the
+// ",omitempty" suffix on your tag to omit that value if it equates to
+// the zero value. The zero value of all types is specified in the Go
+// specification.
+//
+// For example, the zero type of a numeric type is zero ("0"). If the struct
+// field value is zero and a numeric type, the field is empty, and it won't
+// be encoded into the destination type.
+//
+//     type Source {
+//         Age int `mapstructure:",omitempty"`
+//     }
+//
+// Unexported fields
+//
+// Since unexported (private) struct fields cannot be set outside the package
+// where they are defined, the decoder will simply skip them.
+//
+// For this output type definition:
+//
+//     type Exported struct {
+//         private string // this unexported field will be skipped
+//         Public string
+//     }
+//
+// Using this map as input:
+//
+//     map[string]interface{}{
+//         "private": "I will be ignored",
+//         "Public":  "I made it through!",
+//     }
+//
+// The following struct will be decoded:
+//
+//     type Exported struct {
+//         private: "" // field is left with an empty string (zero value)
+//         Public: "I made it through!"
+//     }
+//
+// Other Configuration
+//
+// mapstructure is highly configurable. See the DecoderConfig struct
+// for other features and options that are supported.
+package mapstructure
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"reflect"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// DecodeHookFunc is the callback function that can be used for
+// data transformations. See "DecodeHook" in the DecoderConfig
+// struct.
+//
+// The type must be one of DecodeHookFuncType, DecodeHookFuncKind, or
+// DecodeHookFuncValue.
+// Values are a superset of Types (Values can return types), and Types are a
+// superset of Kinds (Types can return Kinds) and are generally a richer thing
+// to use, but Kinds are simpler if you only need those.
+//
+// The reason DecodeHookFunc is multi-typed is for backwards compatibility:
+// we started with Kinds and then realized Types were the better solution,
+// but have a promise to not break backwards compat so we now support
+// both.
+type DecodeHookFunc interface{}
+
+// DecodeHookFuncType is a DecodeHookFunc which has complete information about
+// the source and target types.
+type DecodeHookFuncType func(reflect.Type, reflect.Type, interface{}) (interface{}, error)
+
+// DecodeHookFuncKind is a DecodeHookFunc which knows only the Kinds of the
+// source and target types.
+type DecodeHookFuncKind func(reflect.Kind, reflect.Kind, interface{}) (interface{}, error)
+
+// DecodeHookFuncRaw is a DecodeHookFunc which has complete access to both the source and target
+// values.
+type DecodeHookFuncValue func(from reflect.Value, to reflect.Value) (interface{}, error)
+
+// DecoderConfig is the configuration that is used to create a new decoder
+// and allows customization of various aspects of decoding.
+type DecoderConfig struct {
+	// DecodeHook, if set, will be called before any decoding and any
+	// type conversion (if WeaklyTypedInput is on). This lets you modify
+	// the values before they're set down onto the resulting struct. The
+	// DecodeHook is called for every map and value in the input. This means
+	// that if a struct has embedded fields with squash tags the decode hook
+	// is called only once with all of the input data, not once for each
+	// embedded struct.
+	//
+	// If an error is returned, the entire decode will fail with that error.
+	DecodeHook DecodeHookFunc
+
+	// If ErrorUnused is true, then it is an error for there to exist
+	// keys in the original map that were unused in the decoding process
+	// (extra keys).
+	ErrorUnused bool
+
+	// ZeroFields, if set to true, will zero fields before writing them.
+	// For example, a map will be emptied before decoded values are put in
+	// it. If this is false, a map will be merged.
+	ZeroFields bool
+
+	// If WeaklyTypedInput is true, the decoder will make the following
+	// "weak" conversions:
+	//
+	//   - bools to string (true = "1", false = "0")
+	//   - numbers to string (base 10)
+	//   - bools to int/uint (true = 1, false = 0)
+	//   - strings to int/uint (base implied by prefix)
+	//   - int to bool (true if value != 0)
+	//   - string to bool (accepts: 1, t, T, TRUE, true, True, 0, f, F,
+	//     FALSE, false, False. Anything else is an error)
+	//   - empty array = empty map and vice versa
+	//   - negative numbers to overflowed uint values (base 10)
+	//   - slice of maps to a merged map
+	//   - single values are converted to slices if required. Each
+	//     element is weakly decoded. For example: "4" can become []int{4}
+	//     if the target type is an int slice.
+	//
+	WeaklyTypedInput bool
+
+	// Squash will squash embedded structs.  A squash tag may also be
+	// added to an individual struct field using a tag.  For example:
+	//
+	//  type Parent struct {
+	//      Child `mapstructure:",squash"`
+	//  }
+	Squash bool
+
+	// Metadata is the struct that will contain extra metadata about
+	// the decoding. If this is nil, then no metadata will be tracked.
+	Metadata *Metadata
+
+	// Result is a pointer to the struct that will contain the decoded
+	// value.
+	Result interface{}
+
+	// The tag name that mapstructure reads for field names. This
+	// defaults to "mapstructure"
+	TagName string
+}
+
+// A Decoder takes a raw interface value and turns it into structured
+// data, keeping track of rich error information along the way in case
+// anything goes wrong. Unlike the basic top-level Decode method, you can
+// more finely control how the Decoder behaves using the DecoderConfig
+// structure. The top-level Decode method is just a convenience that sets
+// up the most basic Decoder.
+type Decoder struct {
+	config *DecoderConfig
+}
+
+// Metadata contains information about decoding a structure that
+// is tedious or difficult to get otherwise.
+type Metadata struct {
+	// Keys are the keys of the structure which were successfully decoded
+	Keys []string
+
+	// Unused is a slice of keys that were found in the raw value but
+	// weren't decoded since there was no matching field in the result interface
+	Unused []string
+}
+
+// Decode takes an input structure and uses reflection to translate it to
+// the output structure. output must be a pointer to a map or struct.
+func Decode(input interface{}, output interface{}) error {
+	config := &DecoderConfig{
+		Metadata: nil,
+		Result:   output,
+	}
+
+	decoder, err := NewDecoder(config)
+	if err != nil {
+		return err
+	}
+
+	return decoder.Decode(input)
+}
+
+// WeakDecode is the same as Decode but is shorthand to enable
+// WeaklyTypedInput. See DecoderConfig for more info.
+func WeakDecode(input, output interface{}) error {
+	config := &DecoderConfig{
+		Metadata:         nil,
+		Result:           output,
+		WeaklyTypedInput: true,
+	}
+
+	decoder, err := NewDecoder(config)
+	if err != nil {
+		return err
+	}
+
+	return decoder.Decode(input)
+}
+
+// DecodeMetadata is the same as Decode, but is shorthand to
+// enable metadata collection. See DecoderConfig for more info.
+func DecodeMetadata(input interface{}, output interface{}, metadata *Metadata) error {
+	config := &DecoderConfig{
+		Metadata: metadata,
+		Result:   output,
+	}
+
+	decoder, err := NewDecoder(config)
+	if err != nil {
+		return err
+	}
+
+	return decoder.Decode(input)
+}
+
+// WeakDecodeMetadata is the same as Decode, but is shorthand to
+// enable both WeaklyTypedInput and metadata collection. See
+// DecoderConfig for more info.
+func WeakDecodeMetadata(input interface{}, output interface{}, metadata *Metadata) error {
+	config := &DecoderConfig{
+		Metadata:         metadata,
+		Result:           output,
+		WeaklyTypedInput: true,
+	}
+
+	decoder, err := NewDecoder(config)
+	if err != nil {
+		return err
+	}
+
+	return decoder.Decode(input)
+}
+
+// NewDecoder returns a new decoder for the given configuration. Once
+// a decoder has been returned, the same configuration must not be used
+// again.
+func NewDecoder(config *DecoderConfig) (*Decoder, error) {
+	val := reflect.ValueOf(config.Result)
+	if val.Kind() != reflect.Ptr {
+		return nil, errors.New("result must be a pointer")
+	}
+
+	val = val.Elem()
+	if !val.CanAddr() {
+		return nil, errors.New("result must be addressable (a pointer)")
+	}
+
+	if config.Metadata != nil {
+		if config.Metadata.Keys == nil {
+			config.Metadata.Keys = make([]string, 0)
+		}
+
+		if config.Metadata.Unused == nil {
+			config.Metadata.Unused = make([]string, 0)
+		}
+	}
+
+	if config.TagName == "" {
+		config.TagName = "mapstructure"
+	}
+
+	result := &Decoder{
+		config: config,
+	}
+
+	return result, nil
+}
+
+// Decode decodes the given raw interface to the target pointer specified
+// by the configuration.
+func (d *Decoder) Decode(input interface{}) error {
+	return d.decode("", input, reflect.ValueOf(d.config.Result).Elem())
+}
+
+// Decodes an unknown data type into a specific reflection value.
+func (d *Decoder) decode(name string, input interface{}, outVal reflect.Value) error {
+	var inputVal reflect.Value
+	if input != nil {
+		inputVal = reflect.ValueOf(input)
+
+		// We need to check here if input is a typed nil. Typed nils won't
+		// match the "input == nil" below so we check that here.
+		if inputVal.Kind() == reflect.Ptr && inputVal.IsNil() {
+			input = nil
+		}
+	}
+
+	if input == nil {
+		// If the data is nil, then we don't set anything, unless ZeroFields is set
+		// to true.
+		if d.config.ZeroFields {
+			outVal.Set(reflect.Zero(outVal.Type()))
+
+			if d.config.Metadata != nil && name != "" {
+				d.config.Metadata.Keys = append(d.config.Metadata.Keys, name)
+			}
+		}
+		return nil
+	}
+
+	if !inputVal.IsValid() {
+		// If the input value is invalid, then we just set the value
+		// to be the zero value.
+		outVal.Set(reflect.Zero(outVal.Type()))
+		if d.config.Metadata != nil && name != "" {
+			d.config.Metadata.Keys = append(d.config.Metadata.Keys, name)
+		}
+		return nil
+	}
+
+	if d.config.DecodeHook != nil {
+		// We have a DecodeHook, so let's pre-process the input.
+		var err error
+		input, err = DecodeHookExec(d.config.DecodeHook, inputVal, outVal)
+		if err != nil {
+			return fmt.Errorf("error decoding '%s': %s", name, err)
+		}
+	}
+
+	var err error
+	outputKind := getKind(outVal)
+	addMetaKey := true
+	switch outputKind {
+	case reflect.Bool:
+		err = d.decodeBool(name, input, outVal)
+	case reflect.Interface:
+		err = d.decodeBasic(name, input, outVal)
+	case reflect.String:
+		err = d.decodeString(name, input, outVal)
+	case reflect.Int:
+		err = d.decodeInt(name, input, outVal)
+	case reflect.Uint:
+		err = d.decodeUint(name, input, outVal)
+	case reflect.Float32:
+		err = d.decodeFloat(name, input, outVal)
+	case reflect.Struct:
+		err = d.decodeStruct(name, input, outVal)
+	case reflect.Map:
+		err = d.decodeMap(name, input, outVal)
+	case reflect.Ptr:
+		addMetaKey, err = d.decodePtr(name, input, outVal)
+	case reflect.Slice:
+		err = d.decodeSlice(name, input, outVal)
+	case reflect.Array:
+		err = d.decodeArray(name, input, outVal)
+	case reflect.Func:
+		err = d.decodeFunc(name, input, outVal)
+	default:
+		// If we reached this point then we weren't able to decode it
+		return fmt.Errorf("%s: unsupported type: %s", name, outputKind)
+	}
+
+	// If we reached here, then we successfully decoded SOMETHING, so
+	// mark the key as used if we're tracking metainput.
+	if addMetaKey && d.config.Metadata != nil && name != "" {
+		d.config.Metadata.Keys = append(d.config.Metadata.Keys, name)
+	}
+
+	return err
+}
+
+// This decodes a basic type (bool, int, string, etc.) and sets the
+// value to "data" of that type.
+func (d *Decoder) decodeBasic(name string, data interface{}, val reflect.Value) error {
+	if val.IsValid() && val.Elem().IsValid() {
+		elem := val.Elem()
+
+		// If we can't address this element, then its not writable. Instead,
+		// we make a copy of the value (which is a pointer and therefore
+		// writable), decode into that, and replace the whole value.
+		copied := false
+		if !elem.CanAddr() {
+			copied = true
+
+			// Make *T
+			copy := reflect.New(elem.Type())
+
+			// *T = elem
+			copy.Elem().Set(elem)
+
+			// Set elem so we decode into it
+			elem = copy
+		}
+
+		// Decode. If we have an error then return. We also return right
+		// away if we're not a copy because that means we decoded directly.
+		if err := d.decode(name, data, elem); err != nil || !copied {
+			return err
+		}
+
+		// If we're a copy, we need to set te final result
+		val.Set(elem.Elem())
+		return nil
+	}
+
+	dataVal := reflect.ValueOf(data)
+
+	// If the input data is a pointer, and the assigned type is the dereference
+	// of that exact pointer, then indirect it so that we can assign it.
+	// Example: *string to string
+	if dataVal.Kind() == reflect.Ptr && dataVal.Type().Elem() == val.Type() {
+		dataVal = reflect.Indirect(dataVal)
+	}
+
+	if !dataVal.IsValid() {
+		dataVal = reflect.Zero(val.Type())
+	}
+
+	dataValType := dataVal.Type()
+	if !dataValType.AssignableTo(val.Type()) {
+		return fmt.Errorf(
+			"'%s' expected type '%s', got '%s'",
+			name, val.Type(), dataValType)
+	}
+
+	val.Set(dataVal)
+	return nil
+}
+
+func (d *Decoder) decodeString(name string, data interface{}, val reflect.Value) error {
+	dataVal := reflect.Indirect(reflect.ValueOf(data))
+	dataKind := getKind(dataVal)
+
+	converted := true
+	switch {
+	case dataKind == reflect.String:
+		val.SetString(dataVal.String())
+	case dataKind == reflect.Bool && d.config.WeaklyTypedInput:
+		if dataVal.Bool() {
+			val.SetString("1")
+		} else {
+			val.SetString("0")
+		}
+	case dataKind == reflect.Int && d.config.WeaklyTypedInput:
+		val.SetString(strconv.FormatInt(dataVal.Int(), 10))
+	case dataKind == reflect.Uint && d.config.WeaklyTypedInput:
+		val.SetString(strconv.FormatUint(dataVal.Uint(), 10))
+	case dataKind == reflect.Float32 && d.config.WeaklyTypedInput:
+		val.SetString(strconv.FormatFloat(dataVal.Float(), 'f', -1, 64))
+	case dataKind == reflect.Slice && d.config.WeaklyTypedInput,
+		dataKind == reflect.Array && d.config.WeaklyTypedInput:
+		dataType := dataVal.Type()
+		elemKind := dataType.Elem().Kind()
+		switch elemKind {
+		case reflect.Uint8:
+			var uints []uint8
+			if dataKind == reflect.Array {
+				uints = make([]uint8, dataVal.Len(), dataVal.Len())
+				for i := range uints {
+					uints[i] = dataVal.Index(i).Interface().(uint8)
+				}
+			} else {
+				uints = dataVal.Interface().([]uint8)
+			}
+			val.SetString(string(uints))
+		default:
+			converted = false
+		}
+	default:
+		converted = false
+	}
+
+	if !converted {
+		return fmt.Errorf(
+			"'%s' expected type '%s', got unconvertible type '%s', value: '%v'",
+			name, val.Type(), dataVal.Type(), data)
+	}
+
+	return nil
+}
+
+func (d *Decoder) decodeInt(name string, data interface{}, val reflect.Value) error {
+	dataVal := reflect.Indirect(reflect.ValueOf(data))
+	dataKind := getKind(dataVal)
+	dataType := dataVal.Type()
+
+	switch {
+	case dataKind == reflect.Int:
+		val.SetInt(dataVal.Int())
+	case dataKind == reflect.Uint:
+		val.SetInt(int64(dataVal.Uint()))
+	case dataKind == reflect.Float32:
+		val.SetInt(int64(dataVal.Float()))
+	case dataKind == reflect.Bool && d.config.WeaklyTypedInput:
+		if dataVal.Bool() {
+			val.SetInt(1)
+		} else {
+			val.SetInt(0)
+		}
+	case dataKind == reflect.String && d.config.WeaklyTypedInput:
+		str := dataVal.String()
+		if str == "" {
+			str = "0"
+		}
+
+		i, err := strconv.ParseInt(str, 0, val.Type().Bits())
+		if err == nil {
+			val.SetInt(i)
+		} else {
+			return fmt.Errorf("cannot parse '%s' as int: %s", name, err)
+		}
+	case dataType.PkgPath() == "encoding/json" && dataType.Name() == "Number":
+		jn := data.(json.Number)
+		i, err := jn.Int64()
+		if err != nil {
+			return fmt.Errorf(
+				"error decoding json.Number into %s: %s", name, err)
+		}
+		val.SetInt(i)
+	default:
+		return fmt.Errorf(
+			"'%s' expected type '%s', got unconvertible type '%s', value: '%v'",
+			name, val.Type(), dataVal.Type(), data)
+	}
+
+	return nil
+}
+
+func (d *Decoder) decodeUint(name string, data interface{}, val reflect.Value) error {
+	dataVal := reflect.Indirect(reflect.ValueOf(data))
+	dataKind := getKind(dataVal)
+	dataType := dataVal.Type()
+
+	switch {
+	case dataKind == reflect.Int:
+		i := dataVal.Int()
+		if i < 0 && !d.config.WeaklyTypedInput {
+			return fmt.Errorf("cannot parse '%s', %d overflows uint",
+				name, i)
+		}
+		val.SetUint(uint64(i))
+	case dataKind == reflect.Uint:
+		val.SetUint(dataVal.Uint())
+	case dataKind == reflect.Float32:
+		f := dataVal.Float()
+		if f < 0 && !d.config.WeaklyTypedInput {
+			return fmt.Errorf("cannot parse '%s', %f overflows uint",
+				name, f)
+		}
+		val.SetUint(uint64(f))
+	case dataKind == reflect.Bool && d.config.WeaklyTypedInput:
+		if dataVal.Bool() {
+			val.SetUint(1)
+		} else {
+			val.SetUint(0)
+		}
+	case dataKind == reflect.String && d.config.WeaklyTypedInput:
+		str := dataVal.String()
+		if str == "" {
+			str = "0"
+		}
+
+		i, err := strconv.ParseUint(str, 0, val.Type().Bits())
+		if err == nil {
+			val.SetUint(i)
+		} else {
+			return fmt.Errorf("cannot parse '%s' as uint: %s", name, err)
+		}
+	case dataType.PkgPath() == "encoding/json" && dataType.Name() == "Number":
+		jn := data.(json.Number)
+		i, err := jn.Int64()
+		if err != nil {
+			return fmt.Errorf(
+				"error decoding json.Number into %s: %s", name, err)
+		}
+		if i < 0 && !d.config.WeaklyTypedInput {
+			return fmt.Errorf("cannot parse '%s', %d overflows uint",
+				name, i)
+		}
+		val.SetUint(uint64(i))
+	default:
+		return fmt.Errorf(
+			"'%s' expected type '%s', got unconvertible type '%s', value: '%v'",
+			name, val.Type(), dataVal.Type(), data)
+	}
+
+	return nil
+}
+
+func (d *Decoder) decodeBool(name string, data interface{}, val reflect.Value) error {
+	dataVal := reflect.Indirect(reflect.ValueOf(data))
+	dataKind := getKind(dataVal)
+
+	switch {
+	case dataKind == reflect.Bool:
+		val.SetBool(dataVal.Bool())
+	case dataKind == reflect.Int && d.config.WeaklyTypedInput:
+		val.SetBool(dataVal.Int() != 0)
+	case dataKind == reflect.Uint && d.config.WeaklyTypedInput:
+		val.SetBool(dataVal.Uint() != 0)
+	case dataKind == reflect.Float32 && d.config.WeaklyTypedInput:
+		val.SetBool(dataVal.Float() != 0)
+	case dataKind == reflect.String && d.config.WeaklyTypedInput:
+		b, err := strconv.ParseBool(dataVal.String())
+		if err == nil {
+			val.SetBool(b)
+		} else if dataVal.String() == "" {
+			val.SetBool(false)
+		} else {
+			return fmt.Errorf("cannot parse '%s' as bool: %s", name, err)
+		}
+	default:
+		return fmt.Errorf(
+			"'%s' expected type '%s', got unconvertible type '%s', value: '%v'",
+			name, val.Type(), dataVal.Type(), data)
+	}
+
+	return nil
+}
+
+func (d *Decoder) decodeFloat(name string, data interface{}, val reflect.Value) error {
+	dataVal := reflect.Indirect(reflect.ValueOf(data))
+	dataKind := getKind(dataVal)
+	dataType := dataVal.Type()
+
+	switch {
+	case dataKind == reflect.Int:
+		val.SetFloat(float64(dataVal.Int()))
+	case dataKind == reflect.Uint:
+		val.SetFloat(float64(dataVal.Uint()))
+	case dataKind == reflect.Float32:
+		val.SetFloat(dataVal.Float())
+	case dataKind == reflect.Bool && d.config.WeaklyTypedInput:
+		if dataVal.Bool() {
+			val.SetFloat(1)
+		} else {
+			val.SetFloat(0)
+		}
+	case dataKind == reflect.String && d.config.WeaklyTypedInput:
+		str := dataVal.String()
+		if str == "" {
+			str = "0"
+		}
+
+		f, err := strconv.ParseFloat(str, val.Type().Bits())
+		if err == nil {
+			val.SetFloat(f)
+		} else {
+			return fmt.Errorf("cannot parse '%s' as float: %s", name, err)
+		}
+	case dataType.PkgPath() == "encoding/json" && dataType.Name() == "Number":
+		jn := data.(json.Number)
+		i, err := jn.Float64()
+		if err != nil {
+			return fmt.Errorf(
+				"error decoding json.Number into %s: %s", name, err)
+		}
+		val.SetFloat(i)
+	default:
+		return fmt.Errorf(
+			"'%s' expected type '%s', got unconvertible type '%s', value: '%v'",
+			name, val.Type(), dataVal.Type(), data)
+	}
+
+	return nil
+}
+
+func (d *Decoder) decodeMap(name string, data interface{}, val reflect.Value) error {
+	valType := val.Type()
+	valKeyType := valType.Key()
+	valElemType := valType.Elem()
+
+	// By default we overwrite keys in the current map
+	valMap := val
+
+	// If the map is nil or we're purposely zeroing fields, make a new map
+	if valMap.IsNil() || d.config.ZeroFields {
+		// Make a new map to hold our result
+		mapType := reflect.MapOf(valKeyType, valElemType)
+		valMap = reflect.MakeMap(mapType)
+	}
+
+	// Check input type and based on the input type jump to the proper func
+	dataVal := reflect.Indirect(reflect.ValueOf(data))
+	switch dataVal.Kind() {
+	case reflect.Map:
+		return d.decodeMapFromMap(name, dataVal, val, valMap)
+
+	case reflect.Struct:
+		return d.decodeMapFromStruct(name, dataVal, val, valMap)
+
+	case reflect.Array, reflect.Slice:
+		if d.config.WeaklyTypedInput {
+			return d.decodeMapFromSlice(name, dataVal, val, valMap)
+		}
+
+		fallthrough
+
+	default:
+		return fmt.Errorf("'%s' expected a map, got '%s'", name, dataVal.Kind())
+	}
+}
+
+func (d *Decoder) decodeMapFromSlice(name string, dataVal reflect.Value, val reflect.Value, valMap reflect.Value) error {
+	// Special case for BC reasons (covered by tests)
+	if dataVal.Len() == 0 {
+		val.Set(valMap)
+		return nil
+	}
+
+	for i := 0; i < dataVal.Len(); i++ {
+		err := d.decode(
+			name+"["+strconv.Itoa(i)+"]",
+			dataVal.Index(i).Interface(), val)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (d *Decoder) decodeMapFromMap(name string, dataVal reflect.Value, val reflect.Value, valMap reflect.Value) error {
+	valType := val.Type()
+	valKeyType := valType.Key()
+	valElemType := valType.Elem()
+
+	// Accumulate errors
+	errors := make([]string, 0)
+
+	// If the input data is empty, then we just match what the input data is.
+	if dataVal.Len() == 0 {
+		if dataVal.IsNil() {
+			if !val.IsNil() {
+				val.Set(dataVal)
+			}
+		} else {
+			// Set to empty allocated value
+			val.Set(valMap)
+		}
+
+		return nil
+	}
+
+	for _, k := range dataVal.MapKeys() {
+		fieldName := name + "[" + k.String() + "]"
+
+		// First decode the key into the proper type
+		currentKey := reflect.Indirect(reflect.New(valKeyType))
+		if err := d.decode(fieldName, k.Interface(), currentKey); err != nil {
+			errors = appendErrors(errors, err)
+			continue
+		}
+
+		// Next decode the data into the proper type
+		v := dataVal.MapIndex(k).Interface()
+		currentVal := reflect.Indirect(reflect.New(valElemType))
+		if err := d.decode(fieldName, v, currentVal); err != nil {
+			errors = appendErrors(errors, err)
+			continue
+		}
+
+		valMap.SetMapIndex(currentKey, currentVal)
+	}
+
+	// Set the built up map to the value
+	val.Set(valMap)
+
+	// If we had errors, return those
+	if len(errors) > 0 {
+		return &Error{errors}
+	}
+
+	return nil
+}
+
+func (d *Decoder) decodeMapFromStruct(name string, dataVal reflect.Value, val reflect.Value, valMap reflect.Value) error {
+	typ := dataVal.Type()
+	for i := 0; i < typ.NumField(); i++ {
+		// Get the StructField first since this is a cheap operation. If the
+		// field is unexported, then ignore it.
+		f := typ.Field(i)
+		if f.PkgPath != "" {
+			continue
+		}
+
+		// Next get the actual value of this field and verify it is assignable
+		// to the map value.
+		v := dataVal.Field(i)
+		if !v.Type().AssignableTo(valMap.Type().Elem()) {
+			return fmt.Errorf("cannot assign type '%s' to map value field of type '%s'", v.Type(), valMap.Type().Elem())
+		}
+
+		tagValue := f.Tag.Get(d.config.TagName)
+		keyName := f.Name
+
+		// If Squash is set in the config, we squash the field down.
+		squash := d.config.Squash && v.Kind() == reflect.Struct && f.Anonymous
+
+		// Determine the name of the key in the map
+		if index := strings.Index(tagValue, ","); index != -1 {
+			if tagValue[:index] == "-" {
+				continue
+			}
+			// If "omitempty" is specified in the tag, it ignores empty values.
+			if strings.Index(tagValue[index+1:], "omitempty") != -1 && isEmptyValue(v) {
+				continue
+			}
+
+			// If "squash" is specified in the tag, we squash the field down.
+			squash = !squash && strings.Index(tagValue[index+1:], "squash") != -1
+			if squash {
+				// When squashing, the embedded type can be a pointer to a struct.
+				if v.Kind() == reflect.Ptr && v.Elem().Kind() == reflect.Struct {
+					v = v.Elem()
+				}
+
+				// The final type must be a struct
+				if v.Kind() != reflect.Struct {
+					return fmt.Errorf("cannot squash non-struct type '%s'", v.Type())
+				}
+			}
+			keyName = tagValue[:index]
+		} else if len(tagValue) > 0 {
+			if tagValue == "-" {
+				continue
+			}
+			keyName = tagValue
+		}
+
+		switch v.Kind() {
+		// this is an embedded struct, so handle it differently
+		case reflect.Struct:
+			x := reflect.New(v.Type())
+			x.Elem().Set(v)
+
+			vType := valMap.Type()
+			vKeyType := vType.Key()
+			vElemType := vType.Elem()
+			mType := reflect.MapOf(vKeyType, vElemType)
+			vMap := reflect.MakeMap(mType)
+
+			// Creating a pointer to a map so that other methods can completely
+			// overwrite the map if need be (looking at you decodeMapFromMap). The
+			// indirection allows the underlying map to be settable (CanSet() == true)
+			// where as reflect.MakeMap returns an unsettable map.
+			addrVal := reflect.New(vMap.Type())
+			reflect.Indirect(addrVal).Set(vMap)
+
+			err := d.decode(keyName, x.Interface(), reflect.Indirect(addrVal))
+			if err != nil {
+				return err
+			}
+
+			// the underlying map may have been completely overwritten so pull
+			// it indirectly out of the enclosing value.
+			vMap = reflect.Indirect(addrVal)
+
+			if squash {
+				for _, k := range vMap.MapKeys() {
+					valMap.SetMapIndex(k, vMap.MapIndex(k))
+				}
+			} else {
+				valMap.SetMapIndex(reflect.ValueOf(keyName), vMap)
+			}
+
+		default:
+			valMap.SetMapIndex(reflect.ValueOf(keyName), v)
+		}
+	}
+
+	if val.CanAddr() {
+		val.Set(valMap)
+	}
+
+	return nil
+}
+
+func (d *Decoder) decodePtr(name string, data interface{}, val reflect.Value) (bool, error) {
+	// If the input data is nil, then we want to just set the output
+	// pointer to be nil as well.
+	isNil := data == nil
+	if !isNil {
+		switch v := reflect.Indirect(reflect.ValueOf(data)); v.Kind() {
+		case reflect.Chan,
+			reflect.Func,
+			reflect.Interface,
+			reflect.Map,
+			reflect.Ptr,
+			reflect.Slice:
+			isNil = v.IsNil()
+		}
+	}
+	if isNil {
+		if !val.IsNil() && val.CanSet() {
+			nilValue := reflect.New(val.Type()).Elem()
+			val.Set(nilValue)
+		}
+
+		return true, nil
+	}
+
+	// Create an element of the concrete (non pointer) type and decode
+	// into that. Then set the value of the pointer to this type.
+	valType := val.Type()
+	valElemType := valType.Elem()
+	if val.CanSet() {
+		realVal := val
+		if realVal.IsNil() || d.config.ZeroFields {
+			realVal = reflect.New(valElemType)
+		}
+
+		if err := d.decode(name, data, reflect.Indirect(realVal)); err != nil {
+			return false, err
+		}
+
+		val.Set(realVal)
+	} else {
+		if err := d.decode(name, data, reflect.Indirect(val)); err != nil {
+			return false, err
+		}
+	}
+	return false, nil
+}
+
+func (d *Decoder) decodeFunc(name string, data interface{}, val reflect.Value) error {
+	// Create an element of the concrete (non pointer) type and decode
+	// into that. Then set the value of the pointer to this type.
+	dataVal := reflect.Indirect(reflect.ValueOf(data))
+	if val.Type() != dataVal.Type() {
+		return fmt.Errorf(
+			"'%s' expected type '%s', got unconvertible type '%s', value: '%v'",
+			name, val.Type(), dataVal.Type(), data)
+	}
+	val.Set(dataVal)
+	return nil
+}
+
+func (d *Decoder) decodeSlice(name string, data interface{}, val reflect.Value) error {
+	dataVal := reflect.Indirect(reflect.ValueOf(data))
+	dataValKind := dataVal.Kind()
+	valType := val.Type()
+	valElemType := valType.Elem()
+	sliceType := reflect.SliceOf(valElemType)
+
+	// If we have a non array/slice type then we first attempt to convert.
+	if dataValKind != reflect.Array && dataValKind != reflect.Slice {
+		if d.config.WeaklyTypedInput {
+			switch {
+			// Slice and array we use the normal logic
+			case dataValKind == reflect.Slice, dataValKind == reflect.Array:
+				break
+
+			// Empty maps turn into empty slices
+			case dataValKind == reflect.Map:
+				if dataVal.Len() == 0 {
+					val.Set(reflect.MakeSlice(sliceType, 0, 0))
+					return nil
+				}
+				// Create slice of maps of other sizes
+				return d.decodeSlice(name, []interface{}{data}, val)
+
+			case dataValKind == reflect.String && valElemType.Kind() == reflect.Uint8:
+				return d.decodeSlice(name, []byte(dataVal.String()), val)
+
+			// All other types we try to convert to the slice type
+			// and "lift" it into it. i.e. a string becomes a string slice.
+			default:
+				// Just re-try this function with data as a slice.
+				return d.decodeSlice(name, []interface{}{data}, val)
+			}
+		}
+
+		return fmt.Errorf(
+			"'%s': source data must be an array or slice, got %s", name, dataValKind)
+	}
+
+	// If the input value is nil, then don't allocate since empty != nil
+	if dataVal.IsNil() {
+		return nil
+	}
+
+	valSlice := val
+	if valSlice.IsNil() || d.config.ZeroFields {
+		// Make a new slice to hold our result, same size as the original data.
+		valSlice = reflect.MakeSlice(sliceType, dataVal.Len(), dataVal.Len())
+	}
+
+	// Accumulate any errors
+	errors := make([]string, 0)
+
+	for i := 0; i < dataVal.Len(); i++ {
+		currentData := dataVal.Index(i).Interface()
+		for valSlice.Len() <= i {
+			valSlice = reflect.Append(valSlice, reflect.Zero(valElemType))
+		}
+		currentField := valSlice.Index(i)
+
+		fieldName := name + "[" + strconv.Itoa(i) + "]"
+		if err := d.decode(fieldName, currentData, currentField); err != nil {
+			errors = appendErrors(errors, err)
+		}
+	}
+
+	// Finally, set the value to the slice we built up
+	val.Set(valSlice)
+
+	// If there were errors, we return those
+	if len(errors) > 0 {
+		return &Error{errors}
+	}
+
+	return nil
+}
+
+func (d *Decoder) decodeArray(name string, data interface{}, val reflect.Value) error {
+	dataVal := reflect.Indirect(reflect.ValueOf(data))
+	dataValKind := dataVal.Kind()
+	valType := val.Type()
+	valElemType := valType.Elem()
+	arrayType := reflect.ArrayOf(valType.Len(), valElemType)
+
+	valArray := val
+
+	if valArray.Interface() == reflect.Zero(valArray.Type()).Interface() || d.config.ZeroFields {
+		// Check input type
+		if dataValKind != reflect.Array && dataValKind != reflect.Slice {
+			if d.config.WeaklyTypedInput {
+				switch {
+				// Empty maps turn into empty arrays
+				case dataValKind == reflect.Map:
+					if dataVal.Len() == 0 {
+						val.Set(reflect.Zero(arrayType))
+						return nil
+					}
+
+				// All other types we try to convert to the array type
+				// and "lift" it into it. i.e. a string becomes a string array.
+				default:
+					// Just re-try this function with data as a slice.
+					return d.decodeArray(name, []interface{}{data}, val)
+				}
+			}
+
+			return fmt.Errorf(
+				"'%s': source data must be an array or slice, got %s", name, dataValKind)
+
+		}
+		if dataVal.Len() > arrayType.Len() {
+			return fmt.Errorf(
+				"'%s': expected source data to have length less or equal to %d, got %d", name, arrayType.Len(), dataVal.Len())
+
+		}
+
+		// Make a new array to hold our result, same size as the original data.
+		valArray = reflect.New(arrayType).Elem()
+	}
+
+	// Accumulate any errors
+	errors := make([]string, 0)
+
+	for i := 0; i < dataVal.Len(); i++ {
+		currentData := dataVal.Index(i).Interface()
+		currentField := valArray.Index(i)
+
+		fieldName := name + "[" + strconv.Itoa(i) + "]"
+		if err := d.decode(fieldName, currentData, currentField); err != nil {
+			errors = appendErrors(errors, err)
+		}
+	}
+
+	// Finally, set the value to the array we built up
+	val.Set(valArray)
+
+	// If there were errors, we return those
+	if len(errors) > 0 {
+		return &Error{errors}
+	}
+
+	return nil
+}
+
+func (d *Decoder) decodeStruct(name string, data interface{}, val reflect.Value) error {
+	dataVal := reflect.Indirect(reflect.ValueOf(data))
+
+	// If the type of the value to write to and the data match directly,
+	// then we just set it directly instead of recursing into the structure.
+	if dataVal.Type() == val.Type() {
+		val.Set(dataVal)
+		return nil
+	}
+
+	dataValKind := dataVal.Kind()
+	switch dataValKind {
+	case reflect.Map:
+		return d.decodeStructFromMap(name, dataVal, val)
+
+	case reflect.Struct:
+		// Not the most efficient way to do this but we can optimize later if
+		// we want to. To convert from struct to struct we go to map first
+		// as an intermediary.
+
+		// Make a new map to hold our result
+		mapType := reflect.TypeOf((map[string]interface{})(nil))
+		mval := reflect.MakeMap(mapType)
+
+		// Creating a pointer to a map so that other methods can completely
+		// overwrite the map if need be (looking at you decodeMapFromMap). The
+		// indirection allows the underlying map to be settable (CanSet() == true)
+		// where as reflect.MakeMap returns an unsettable map.
+		addrVal := reflect.New(mval.Type())
+
+		reflect.Indirect(addrVal).Set(mval)
+		if err := d.decodeMapFromStruct(name, dataVal, reflect.Indirect(addrVal), mval); err != nil {
+			return err
+		}
+
+		result := d.decodeStructFromMap(name, reflect.Indirect(addrVal), val)
+		return result
+
+	default:
+		return fmt.Errorf("'%s' expected a map, got '%s'", name, dataVal.Kind())
+	}
+}
+
+func (d *Decoder) decodeStructFromMap(name string, dataVal, val reflect.Value) error {
+	dataValType := dataVal.Type()
+	if kind := dataValType.Key().Kind(); kind != reflect.String && kind != reflect.Interface {
+		return fmt.Errorf(
+			"'%s' needs a map with string keys, has '%s' keys",
+			name, dataValType.Key().Kind())
+	}
+
+	dataValKeys := make(map[reflect.Value]struct{})
+	dataValKeysUnused := make(map[interface{}]struct{})
+	for _, dataValKey := range dataVal.MapKeys() {
+		dataValKeys[dataValKey] = struct{}{}
+		dataValKeysUnused[dataValKey.Interface()] = struct{}{}
+	}
+
+	errors := make([]string, 0)
+
+	// This slice will keep track of all the structs we'll be decoding.
+	// There can be more than one struct if there are embedded structs
+	// that are squashed.
+	structs := make([]reflect.Value, 1, 5)
+	structs[0] = val
+
+	// Compile the list of all the fields that we're going to be decoding
+	// from all the structs.
+	type field struct {
+		field reflect.StructField
+		val   reflect.Value
+	}
+
+	// remainField is set to a valid field set with the "remain" tag if
+	// we are keeping track of remaining values.
+	var remainField *field
+
+	fields := []field{}
+	for len(structs) > 0 {
+		structVal := structs[0]
+		structs = structs[1:]
+
+		structType := structVal.Type()
+
+		for i := 0; i < structType.NumField(); i++ {
+			fieldType := structType.Field(i)
+			fieldVal := structVal.Field(i)
+			if fieldVal.Kind() == reflect.Ptr && fieldVal.Elem().Kind() == reflect.Struct {
+				// Handle embedded struct pointers as embedded structs.
+				fieldVal = fieldVal.Elem()
+			}
+
+			// If "squash" is specified in the tag, we squash the field down.
+			squash := d.config.Squash && fieldVal.Kind() == reflect.Struct && fieldType.Anonymous
+			remain := false
+
+			// We always parse the tags cause we're looking for other tags too
+			tagParts := strings.Split(fieldType.Tag.Get(d.config.TagName), ",")
+			for _, tag := range tagParts[1:] {
+				if tag == "squash" {
+					squash = true
+					break
+				}
+
+				if tag == "remain" {
+					remain = true
+					break
+				}
+			}
+
+			if squash {
+				if fieldVal.Kind() != reflect.Struct {
+					errors = appendErrors(errors,
+						fmt.Errorf("%s: unsupported type for squash: %s", fieldType.Name, fieldVal.Kind()))
+				} else {
+					structs = append(structs, fieldVal)
+				}
+				continue
+			}
+
+			// Build our field
+			if remain {
+				remainField = &field{fieldType, fieldVal}
+			} else {
+				// Normal struct field, store it away
+				fields = append(fields, field{fieldType, fieldVal})
+			}
+		}
+	}
+
+	// for fieldType, field := range fields {
+	for _, f := range fields {
+		field, fieldValue := f.field, f.val
+		fieldName := field.Name
+
+		tagValue := field.Tag.Get(d.config.TagName)
+		tagValue = strings.SplitN(tagValue, ",", 2)[0]
+		if tagValue != "" {
+			fieldName = tagValue
+		}
+
+		rawMapKey := reflect.ValueOf(fieldName)
+		rawMapVal := dataVal.MapIndex(rawMapKey)
+		if !rawMapVal.IsValid() {
+			// Do a slower search by iterating over each key and
+			// doing case-insensitive search.
+			for dataValKey := range dataValKeys {
+				mK, ok := dataValKey.Interface().(string)
+				if !ok {
+					// Not a string key
+					continue
+				}
+
+				if strings.EqualFold(mK, fieldName) {
+					rawMapKey = dataValKey
+					rawMapVal = dataVal.MapIndex(dataValKey)
+					break
+				}
+			}
+
+			if !rawMapVal.IsValid() {
+				// There was no matching key in the map for the value in
+				// the struct. Just ignore.
+				continue
+			}
+		}
+
+		if !fieldValue.IsValid() {
+			// This should never happen
+			panic("field is not valid")
+		}
+
+		// If we can't set the field, then it is unexported or something,
+		// and we just continue onwards.
+		if !fieldValue.CanSet() {
+			continue
+		}
+
+		// Delete the key we're using from the unused map so we stop tracking
+		delete(dataValKeysUnused, rawMapKey.Interface())
+
+		// If the name is empty string, then we're at the root, and we
+		// don't dot-join the fields.
+		if name != "" {
+			fieldName = name + "." + fieldName
+		}
+
+		if err := d.decode(fieldName, rawMapVal.Interface(), fieldValue); err != nil {
+			errors = appendErrors(errors, err)
+		}
+	}
+
+	// If we have a "remain"-tagged field and we have unused keys then
+	// we put the unused keys directly into the remain field.
+	if remainField != nil && len(dataValKeysUnused) > 0 {
+		// Build a map of only the unused values
+		remain := map[interface{}]interface{}{}
+		for key := range dataValKeysUnused {
+			remain[key] = dataVal.MapIndex(reflect.ValueOf(key)).Interface()
+		}
+
+		// Decode it as-if we were just decoding this map onto our map.
+		if err := d.decodeMap(name, remain, remainField.val); err != nil {
+			errors = appendErrors(errors, err)
+		}
+
+		// Set the map to nil so we have none so that the next check will
+		// not error (ErrorUnused)
+		dataValKeysUnused = nil
+	}
+
+	if d.config.ErrorUnused && len(dataValKeysUnused) > 0 {
+		keys := make([]string, 0, len(dataValKeysUnused))
+		for rawKey := range dataValKeysUnused {
+			keys = append(keys, rawKey.(string))
+		}
+		sort.Strings(keys)
+
+		err := fmt.Errorf("'%s' has invalid keys: %s", name, strings.Join(keys, ", "))
+		errors = appendErrors(errors, err)
+	}
+
+	if len(errors) > 0 {
+		return &Error{errors}
+	}
+
+	// Add the unused keys to the list of unused keys if we're tracking metadata
+	if d.config.Metadata != nil {
+		for rawKey := range dataValKeysUnused {
+			key := rawKey.(string)
+			if name != "" {
+				key = name + "." + key
+			}
+
+			d.config.Metadata.Unused = append(d.config.Metadata.Unused, key)
+		}
+	}
+
+	return nil
+}
+
+func isEmptyValue(v reflect.Value) bool {
+	switch getKind(v) {
+	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
+		return v.Len() == 0
+	case reflect.Bool:
+		return !v.Bool()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return v.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return v.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return v.Float() == 0
+	case reflect.Interface, reflect.Ptr:
+		return v.IsNil()
+	}
+	return false
+}
+
+func getKind(val reflect.Value) reflect.Kind {
+	kind := val.Kind()
+
+	switch {
+	case kind >= reflect.Int && kind <= reflect.Int64:
+		return reflect.Int
+	case kind >= reflect.Uint && kind <= reflect.Uint64:
+		return reflect.Uint
+	case kind >= reflect.Float32 && kind <= reflect.Float64:
+		return reflect.Float32
+	default:
+		return kind
+	}
+}