sizeof_test.go

Documentation: go/types

		 1  // Copyright 2021 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 types
		 6  
		 7  import (
		 8  	"reflect"
		 9  	"testing"
		10  )
		11  
		12  // Signal size changes of important structures.
		13  func TestSizeof(t *testing.T) {
		14  	const _64bit = ^uint(0)>>32 != 0
		15  
		16  	var tests = []struct {
		17  		val		interface{} // type as a value
		18  		_32bit uintptr		 // size on 32bit platforms
		19  		_64bit uintptr		 // size on 64bit platforms
		20  	}{
		21  		// Types
		22  		{Basic{}, 16, 32},
		23  		{Array{}, 16, 24},
		24  		{Slice{}, 8, 16},
		25  		{Struct{}, 24, 48},
		26  		{Pointer{}, 8, 16},
		27  		{Tuple{}, 12, 24},
		28  		{Signature{}, 44, 88},
		29  		{_Sum{}, 12, 24},
		30  		{Interface{}, 60, 120},
		31  		{Map{}, 16, 32},
		32  		{Chan{}, 12, 24},
		33  		{Named{}, 64, 128},
		34  		{_TypeParam{}, 28, 48},
		35  		{instance{}, 44, 88},
		36  		{bottom{}, 0, 0},
		37  		{top{}, 0, 0},
		38  
		39  		// Objects
		40  		{PkgName{}, 48, 88},
		41  		{Const{}, 48, 88},
		42  		{TypeName{}, 40, 72},
		43  		{Var{}, 44, 80},
		44  		{Func{}, 44, 80},
		45  		{Label{}, 44, 80},
		46  		{Builtin{}, 44, 80},
		47  		{Nil{}, 40, 72},
		48  
		49  		// Misc
		50  		{Scope{}, 40, 80},
		51  		{Package{}, 40, 80},
		52  	}
		53  	for _, test := range tests {
		54  		got := reflect.TypeOf(test.val).Size()
		55  		want := test._32bit
		56  		if _64bit {
		57  			want = test._64bit
		58  		}
		59  		if got != want {
		60  			t.Errorf("unsafe.Sizeof(%T) = %d, want %d", test.val, got, want)
		61  		}
		62  	}
		63  }
		64
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