zeros.go

Documentation: golang.org/x/tools/go/ssa/interp/testdata

     1  // Copyright 2022 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  // Test interpretation on zero values with type params.
     6  package zeros
     7  
     8  func assert(cond bool, msg string) {
     9  	if !cond {
    10  		panic(msg)
    11  	}
    12  }
    13  
    14  func tp0[T int | string | float64]() T { return T(0) }
    15  
    16  func tpFalse[T ~bool]() T { return T(false) }
    17  
    18  func tpEmptyString[T string | []byte]() T { return T("") }
    19  
    20  func tpNil[T *int | []byte]() T { return T(nil) }
    21  
    22  func main() {
    23  	// zero values
    24  	var zi int
    25  	var zf float64
    26  	var zs string
    27  
    28  	assert(zi == int(0), "zero value of int is int(0)")
    29  	assert(zf == float64(0), "zero value of float64 is float64(0)")
    30  	assert(zs != string(0), "zero value of string is not string(0)")
    31  
    32  	assert(zi == tp0[int](), "zero value of int is int(0)")
    33  	assert(zf == tp0[float64](), "zero value of float64 is float64(0)")
    34  	assert(zs != tp0[string](), "zero value of string is not string(0)")
    35  
    36  	assert(zf == -0.0, "constant -0.0 is converted to 0.0")
    37  
    38  	assert(!tpFalse[bool](), "zero value of bool is false")
    39  
    40  	assert(tpEmptyString[string]() == zs, `zero value of string is string("")`)
    41  	assert(len(tpEmptyString[[]byte]()) == 0, `[]byte("") is empty`)
    42  
    43  	assert(tpNil[*int]() == nil, "nil is nil")
    44  	assert(tpNil[[]byte]() == nil, "nil is nil")
    45  }
    46
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