github.com/shogo82148/std@v1.22.1-0.20240327122250-4e474527810c/cmd/compile/internal/types2/alias.go (about)

     1  // Copyright 2023 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package types2
     6  
     7  // An Alias represents an alias type.
     8  // Whether or not Alias types are created is controlled by the
     9  // gotypesalias setting with the GODEBUG environment variable.
    10  // For gotypesalias=1, alias declarations produce an Alias type.
    11  // Otherwise, the alias information is only in the type name,
    12  // which points directly to the actual (aliased) type.
    13  type Alias struct {
    14  	obj     *TypeName
    15  	tparams *TypeParamList
    16  	fromRHS Type
    17  	actual  Type
    18  }
    19  
    20  // NewAlias creates a new Alias type with the given type name and rhs.
    21  // rhs must not be nil.
    22  func NewAlias(obj *TypeName, rhs Type) *Alias
    23  
    24  func (a *Alias) Obj() *TypeName
    25  func (a *Alias) Underlying() Type
    26  func (a *Alias) String() string
    27  
    28  // Unalias returns t if it is not an alias type;
    29  // otherwise it follows t's alias chain until it
    30  // reaches a non-alias type which is then returned.
    31  // Consequently, the result is never an alias type.
    32  func Unalias(t Type) Type