// run // Copyright 2009 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 that basic operations on named types are valid // and preserve the type. package main type Array [10]byte type Bool bool type Chan chan int type Float float32 type Int int type Map map[int]byte type Slice []byte type String string // Calling these functions checks at compile time that the argument // can be converted implicitly to (used as) the given type. func asArray(Array) {} func asBool(Bool) {} func asChan(Chan) {} func asFloat(Float) {} func asInt(Int) {} func asMap(Map) {} func asSlice(Slice) {} func asString(String) {} func (Map) M() {} // These functions check at run time that the default type // (in the absence of any implicit conversion hints) // is the given type. func isArray(x interface{}) { _ = x.(Array) } func isBool(x interface{}) { _ = x.(Bool) } func isChan(x interface{}) { _ = x.(Chan) } func isFloat(x interface{}) { _ = x.(Float) } func isInt(x interface{}) { _ = x.(Int) } func isMap(x interface{}) { _ = x.(Map) } func isSlice(x interface{}) { _ = x.(Slice) } func isString(x interface{}) { _ = x.(String) } func main() { var ( a Array b Bool = true c Chan = make(Chan) f Float = 1 i Int = 1 m Map = make(Map) slice Slice = make(Slice, 10) str String = "hello" ) asArray(a) isArray(a) asArray(*&a) isArray(*&a) asArray(Array{}) isArray(Array{}) asBool(b) isBool(b) asBool(!b) isBool(!b) asBool(true) asBool(*&b) isBool(*&b) asBool(Bool(true)) isBool(Bool(true)) asChan(c) isChan(c) asChan(make(Chan)) isChan(make(Chan)) asChan(*&c) isChan(*&c) asChan(Chan(nil)) isChan(Chan(nil)) asFloat(f) isFloat(f) asFloat(-f) isFloat(-f) asFloat(+f) isFloat(+f) asFloat(f + 1) isFloat(f + 1) asFloat(1 + f) isFloat(1 + f) asFloat(f + f) isFloat(f + f) f++ f += 2 asFloat(f - 1) isFloat(f - 1) asFloat(1 - f) isFloat(1 - f) asFloat(f - f) isFloat(f - f) f-- f -= 2 asFloat(f * 2.5) isFloat(f * 2.5) asFloat(2.5 * f) isFloat(2.5 * f) asFloat(f * f) isFloat(f * f) f *= 4 asFloat(f / 2.5) isFloat(f / 2.5) asFloat(2.5 / f) isFloat(2.5 / f) asFloat(f / f) isFloat(f / f) f /= 4 asFloat(f) isFloat(f) f = 5 asFloat(*&f) isFloat(*&f) asFloat(234) asFloat(Float(234)) isFloat(Float(234)) asFloat(1.2) asFloat(Float(i)) isFloat(Float(i)) asInt(i) isInt(i) asInt(-i) isInt(-i) asInt(^i) isInt(^i) asInt(+i) isInt(+i) asInt(i + 1) isInt(i + 1) asInt(1 + i) isInt(1 + i) asInt(i + i) isInt(i + i) i++ i += 1 asInt(i - 1) isInt(i - 1) asInt(1 - i) isInt(1 - i) asInt(i - i) isInt(i - i) i-- i -= 1 asInt(i * 2) isInt(i * 2) asInt(2 * i) isInt(2 * i) asInt(i * i) isInt(i * i) i *= 2 asInt(i / 5) isInt(i / 5) asInt(5 / i) isInt(5 / i) asInt(i / i) isInt(i / i) i /= 2 asInt(i % 5) isInt(i % 5) asInt(5 % i) isInt(5 % i) asInt(i % i) isInt(i % i) i %= 2 asInt(i & 5) isInt(i & 5) asInt(5 & i) isInt(5 & i) asInt(i & i) isInt(i & i) i &= 2 asInt(i &^ 5) isInt(i &^ 5) asInt(5 &^ i) isInt(5 &^ i) asInt(i &^ i) isInt(i &^ i) i &^= 2 asInt(i | 5) isInt(i | 5) asInt(5 | i) isInt(5 | i) asInt(i | i) isInt(i | i) i |= 2 asInt(i ^ 5) isInt(i ^ 5) asInt(5 ^ i) isInt(5 ^ i) asInt(i ^ i) isInt(i ^ i) i ^= 2 asInt(i << 4) isInt(i << 4) i <<= 2 asInt(i >> 4) isInt(i >> 4) i >>= 2 asInt(i) isInt(i) asInt(0) asInt(Int(0)) isInt(Int(0)) i = 10 asInt(*&i) isInt(*&i) asInt(23) asInt(Int(f)) isInt(Int(f)) asMap(m) isMap(m) asMap(nil) m = nil asMap(make(Map)) isMap(make(Map)) asMap(*&m) isMap(*&m) asMap(Map(nil)) isMap(Map(nil)) asMap(Map{}) isMap(Map{}) asSlice(slice) isSlice(slice) asSlice(make(Slice, 5)) isSlice(make(Slice, 5)) asSlice([]byte{1, 2, 3}) asSlice([]byte{1, 2, 3}[0:2]) asSlice(slice[0:4]) isSlice(slice[0:4]) asSlice(slice[3:8]) isSlice(slice[3:8]) asSlice(nil) asSlice(Slice(nil)) isSlice(Slice(nil)) slice = nil asSlice(Slice{1, 2, 3}) isSlice(Slice{1, 2, 3}) asSlice(Slice{}) isSlice(Slice{}) asSlice(*&slice) isSlice(*&slice) asString(str) isString(str) asString(str + "a") isString(str + "a") asString("a" + str) isString("a" + str) asString(str + str) isString(str + str) str += "a" str += str asString(String('a')) isString(String('a')) asString(String([]byte(slice))) isString(String([]byte(slice))) asString(String([]byte(nil))) isString(String([]byte(nil))) asString("hello") asString(String("hello")) isString(String("hello")) str = "hello" isString(str) asString(*&str) isString(*&str) }