Text file src/go/types/testdata/check/builtins.go2

     1  // Copyright 2020 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  // This file tests built-in calls on generic types.
     6  
     7  package builtins
     8  
     9  import "unsafe"
    10  
    11  // close
    12  
    13  type C0 interface{ int }
    14  type C1 interface{ chan int }
    15  type C2 interface{ chan int | <-chan int }
    16  type C3 interface{ chan int | chan float32 }
    17  type C4 interface{ chan int | chan<- int }
    18  type C5[T any] interface{ ~chan T | chan<- T }
    19  
    20  func _[T any](ch T) {
    21  	close(ch /* ERROR cannot close non-channel */)
    22  }
    23  
    24  func _[T C0](ch T) {
    25  	close(ch /* ERROR cannot close non-channel */)
    26  }
    27  
    28  func _[T C1](ch T) {
    29  	close(ch)
    30  }
    31  
    32  func _[T C2](ch T) {
    33  	close(ch /* ERROR cannot close receive-only channel */)
    34  }
    35  
    36  func _[T C3](ch T) {
    37  	close(ch)
    38  }
    39  
    40  func _[T C4](ch T) {
    41  	close(ch)
    42  }
    43  
    44  func _[T C5[X], X any](ch T) {
    45  	close(ch)
    46  }
    47  
    48  // copy
    49  
    50  func _[T any](x, y T) {
    51  	copy(x /* ERROR copy expects slice arguments */ , y)
    52  }
    53  
    54  func _[T ~[]byte](x, y T) {
    55  	copy(x, y)
    56  	copy(x, "foo")
    57  	copy("foo" /* ERROR expects slice arguments */ , y)
    58  
    59  	var x2 []byte
    60  	copy(x2, y) // element types are identical
    61  	copy(y, x2) // element types are identical
    62  
    63  	type myByte byte
    64  	var x3 []myByte
    65  	copy(x3 /* ERROR different element types */ , y)
    66  	copy(y /* ERROR different element types */ , x3)
    67  }
    68  
    69  func _[T ~[]E, E any](x T, y []E) {
    70  	copy(x, y)
    71  	copy(x /* ERROR different element types */ , "foo")
    72  }
    73  
    74  func _[T ~string](x []byte, y T) {
    75  	copy(x, y)
    76  	copy(y /* ERROR expects slice arguments */ , x)
    77  }
    78  
    79  func _[T ~[]byte|~string](x T, y []byte) {
    80  	copy(x /* ERROR expects slice arguments */ , y)
    81  	copy(y, x)
    82  }
    83  
    84  type L0 []int
    85  type L1 []int
    86  
    87  func _[T L0 | L1](x, y T) {
    88  	copy(x, y)
    89  }
    90  
    91  // delete
    92  
    93  type M0 interface{ int }
    94  type M1 interface{ map[string]int }
    95  type M2 interface { map[string]int | map[string]float64 }
    96  type M3 interface{ map[string]int | map[rune]int }
    97  type M4[K comparable, V any] interface{ map[K]V | map[rune]V }
    98  
    99  func _[T any](m T) {
   100  	delete(m /* ERROR not a map */, "foo")
   101  }
   102  
   103  func _[T M0](m T) {
   104  	delete(m /* ERROR not a map */, "foo")
   105  }
   106  
   107  func _[T M1](m T) {
   108  	delete(m, "foo")
   109  }
   110  
   111  func _[T M2](m T) {
   112  	delete(m, "foo")
   113  	delete(m, 0 /* ERROR cannot use .* as string */)
   114  }
   115  
   116  func _[T M3](m T) {
   117  	delete(m /* ERROR must have identical key types */, "foo")
   118  }
   119  
   120  func _[T M4[rune, V], V any](m T) {
   121  	delete(m, 'k')
   122  }
   123  
   124  func _[T M4[K, V], K comparable, V any](m T) {
   125  	delete(m /* ERROR must have identical key types */, "foo")
   126  }
   127  
   128  // make
   129  
   130  type myChan chan int
   131  
   132  func _[
   133  	S1 ~[]int,
   134  	S2 ~[]int | ~chan int,
   135  
   136  	M1 ~map[string]int,
   137  	M2 ~map[string]int | ~chan int,
   138  
   139  	C1 ~chan int,
   140  	C2 ~chan int | ~chan string,
   141  	C3 chan int | myChan, // single underlying type
   142  ]() {
   143  	type S0 []int
   144  	_ = make([]int, 10)
   145  	_ = make(S0, 10)
   146  	_ = make(S1, 10)
   147  	_ = make() /* ERROR not enough arguments */
   148  	_ = make /* ERROR expects 2 or 3 arguments */ (S1)
   149  	_ = make(S1, 10, 20)
   150  	_ = make /* ERROR expects 2 or 3 arguments */ (S1, 10, 20, 30)
   151  	_ = make(S2 /* ERROR cannot make S2: no core type */ , 10)
   152  
   153  	type M0 map[string]int
   154  	_ = make(map[string]int)
   155  	_ = make(M0)
   156  	_ = make(M1)
   157  	_ = make(M1, 10)
   158  	_ = make/* ERROR expects 1 or 2 arguments */(M1, 10, 20)
   159  	_ = make(M2 /* ERROR cannot make M2: no core type */ )
   160  
   161  	type C0 chan int
   162  	_ = make(chan int)
   163  	_ = make(C0)
   164  	_ = make(C1)
   165  	_ = make(C1, 10)
   166  	_ = make/* ERROR expects 1 or 2 arguments */(C1, 10, 20)
   167  	_ = make(C2 /* ERROR cannot make C2: no core type */ )
   168  	_ = make(C3)
   169  }
   170  
   171  // unsafe.Alignof
   172  
   173  func _[T comparable]() {
   174  	var (
   175  		b int64
   176  		a [10]T
   177  		s struct{ f T }
   178  		p *T
   179  		l []T
   180  		f func(T)
   181  		i interface{ m() T }
   182  		c chan T
   183  		m map[T]T
   184  		t T
   185  	)
   186  
   187  	const bb = unsafe.Alignof(b)
   188  	assert(bb == 8)
   189  	const _ = unsafe /* ERROR not constant */ .Alignof(a)
   190  	const _ = unsafe /* ERROR not constant */ .Alignof(s)
   191  	const pp = unsafe.Alignof(p)
   192  	assert(pp == 8)
   193  	const ll = unsafe.Alignof(l)
   194  	assert(ll == 8)
   195  	const ff = unsafe.Alignof(f)
   196  	assert(ff == 8)
   197  	const ii = unsafe.Alignof(i)
   198  	assert(ii == 8)
   199  	const cc = unsafe.Alignof(c)
   200  	assert(cc == 8)
   201  	const mm = unsafe.Alignof(m)
   202  	assert(mm == 8)
   203  	const _ = unsafe /* ERROR not constant */ .Alignof(t)
   204  }
   205  
   206  // unsafe.Offsetof
   207  
   208  func _[T comparable]() {
   209  	var (
   210  		b struct{ _, f int64 }
   211  		a struct{ _, f [10]T }
   212  		s struct{ _, f struct{ f T } }
   213  		p struct{ _, f *T }
   214  		l struct{ _, f []T }
   215  		f struct{ _, f func(T) }
   216  		i struct{ _, f interface{ m() T } }
   217  		c struct{ _, f chan T }
   218  		m struct{ _, f map[T]T }
   219  		t struct{ _, f T }
   220  	)
   221  
   222  	const bb = unsafe.Offsetof(b.f)
   223  	assert(bb == 8)
   224  	const _ = unsafe /* ERROR not constant */ .Alignof(a)
   225  	const _ = unsafe /* ERROR not constant */ .Alignof(s)
   226  	const pp = unsafe.Offsetof(p.f)
   227  	assert(pp == 8)
   228  	const ll = unsafe.Offsetof(l.f)
   229  	assert(ll == 24)
   230  	const ff = unsafe.Offsetof(f.f)
   231  	assert(ff == 8)
   232  	const ii = unsafe.Offsetof(i.f)
   233  	assert(ii == 16)
   234  	const cc = unsafe.Offsetof(c.f)
   235  	assert(cc == 8)
   236  	const mm = unsafe.Offsetof(m.f)
   237  	assert(mm == 8)
   238  	const _ = unsafe /* ERROR not constant */ .Alignof(t)
   239  }
   240  
   241  // unsafe.Sizeof
   242  
   243  func _[T comparable]() {
   244  	var (
   245  		b int64
   246  		a [10]T
   247  		s struct{ f T }
   248  		p *T
   249  		l []T
   250  		f func(T)
   251  		i interface{ m() T }
   252  		c chan T
   253  		m map[T]T
   254  		t T
   255  	)
   256  
   257  	const bb = unsafe.Sizeof(b)
   258  	assert(bb == 8)
   259  	const _ = unsafe /* ERROR not constant */ .Alignof(a)
   260  	const _ = unsafe /* ERROR not constant */ .Alignof(s)
   261  	const pp = unsafe.Sizeof(p)
   262  	assert(pp == 8)
   263  	const ll = unsafe.Sizeof(l)
   264  	assert(ll == 24)
   265  	const ff = unsafe.Sizeof(f)
   266  	assert(ff == 8)
   267  	const ii = unsafe.Sizeof(i)
   268  	assert(ii == 16)
   269  	const cc = unsafe.Sizeof(c)
   270  	assert(cc == 8)
   271  	const mm = unsafe.Sizeof(m)
   272  	assert(mm == 8)
   273  	const _ = unsafe /* ERROR not constant */ .Alignof(t)
   274  }
   275  

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