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https://github.com/golang/go
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15ad61aff5
The general idea is that we now export/import typeparams, typeparam lists for generic types and functions, and instantiated types (instantiations of generic types with either new typeparams or concrete types). This changes the export format -- the next CL in the stack adds the export versions and checks for it in the appropriate places. We always export/import generic function bodies, using the same code that we use for exporting/importing the bodies of inlineable functions. To avoid complicated scoping, we consider all type params as unique and give them unique names for types1. We therefore include the types2 ids (subscripts) in the export format and re-create on import. We always access the same unique types1 typeParam type for the same typeparam name. We create fully-instantiated generic types and functions in the original source package. We do an extra NeedRuntimeType() call to make sure that the correct DWARF information is written out. We call SetDupOK(true) for the functions/methods to have the linker automatically drop duplicate instantiations. Other miscellaneous details: - Export/import of typeparam bounds works for methods (but not typelists) for now, but will change with the typeset changes. - Added a new types.Instantiate function roughly analogous to the types2.Instantiate function recently added. - Always access methods info from the original/base generic type, since the methods of an instantiated type are not filled in (in types2 or types1). - New field OrigSym in types.Type to keep track of base generic type that instantiated type was based on. We use the generic type's symbol (OrigSym) as the link, rather than a Type pointer, since we haven't always created the base type yet when we want to set the link (during types2 to types1 conversion). - Added types2.AsTypeParam(), (*types2.TypeParam).SetId() - New test minimp.dir, which tests use of generic function Min across packages. Another test stringimp.dir, which also exports a generic function Stringify across packages, where the type param has a bound (Stringer) as well. New test pairimp.dir, which tests use of generic type Pair (with no methods) across packages. - New test valimp.dir, which tests use of generic type (with methods and related functions) across packages. - Modified several other tests (adder.go, settable.go, smallest.go, stringable.go, struct.go, sum.go) to export their generic functions/types to show that generic functions/types can be exported successfully (but this doesn't test import). Change-Id: Ie61ce9d54a46d368ddc7a76c41399378963bb57f Reviewed-on: https://go-review.googlesource.com/c/go/+/319930 Trust: Dan Scales <danscales@google.com> Trust: Robert Griesemer <gri@golang.org> Run-TryBot: Dan Scales <danscales@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
50 lines
991 B
Go
50 lines
991 B
Go
// run -gcflags=-G=3
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// Copyright 2021 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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import (
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"fmt"
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)
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type Ordered interface {
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type int, int64, float64, string
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}
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func min[T Ordered](x, y T) T {
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if x < y {
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return x
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}
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return y
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}
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func main() {
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const want = 2
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if got := min[int](2, 3); got != want {
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panic(fmt.Sprintf("got %d, want %d", got, want))
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}
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if got := min(2, 3); got != want {
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panic(fmt.Sprintf("want %d, got %d", want, got))
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}
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if got := min[float64](3.5, 2.0); got != want {
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panic(fmt.Sprintf("got %d, want %d", got, want))
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}
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if got := min(3.5, 2.0); got != want {
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panic(fmt.Sprintf("got %d, want %d", got, want))
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}
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const want2 = "ay"
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if got := min[string]("bb", "ay"); got != want2 {
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panic(fmt.Sprintf("got %d, want %d", got, want2))
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}
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if got := min("bb", "ay"); got != want2 {
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panic(fmt.Sprintf("got %d, want %d", got, want2))
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}
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}
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