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Diffstat (limited to '')
-rw-r--r-- | test/convert4.go | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/test/convert4.go b/test/convert4.go new file mode 100644 index 0000000..2bc9c96 --- /dev/null +++ b/test/convert4.go @@ -0,0 +1,86 @@ +// run + +// Copyright 2020 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Test conversion from slice to array pointer. + +package main + +func wantPanic(fn func(), s string) { + defer func() { + err := recover() + if err == nil { + panic("expected panic") + } + if got := err.(error).Error(); got != s { + panic("expected panic " + s + " got " + got) + } + }() + fn() +} + +func main() { + s := make([]byte, 8, 10) + if p := (*[8]byte)(s); &p[0] != &s[0] { + panic("*[8]byte conversion failed") + } + wantPanic( + func() { + _ = (*[9]byte)(s) + }, + "runtime error: cannot convert slice with length 8 to pointer to array with length 9", + ) + + var n []byte + if p := (*[0]byte)(n); p != nil { + panic("nil slice converted to *[0]byte should be nil") + } + + z := make([]byte, 0) + if p := (*[0]byte)(z); p == nil { + panic("empty slice converted to *[0]byte should be non-nil") + } + + // Test with named types + type Slice []int + type Int4 [4]int + type PInt4 *[4]int + ii := make(Slice, 4) + if p := (*Int4)(ii); &p[0] != &ii[0] { + panic("*Int4 conversion failed") + } + if p := PInt4(ii); &p[0] != &ii[0] { + panic("PInt4 conversion failed") + } +} + +// test static variable conversion + +var ( + ss = make([]string, 10) + s5 = (*[5]string)(ss) + s10 = (*[10]string)(ss) + + ns []string + ns0 = (*[0]string)(ns) + + zs = make([]string, 0) + zs0 = (*[0]string)(zs) +) + +func init() { + if &ss[0] != &s5[0] { + panic("s5 conversion failed") + } + if &ss[0] != &s10[0] { + panic("s5 conversion failed") + } + if ns0 != nil { + panic("ns0 should be nil") + } + if zs0 == nil { + panic("zs0 should not be nil") + } +} |