“嵌套"带括号的类模板参数推导:GCC与clang [英] "Nested" class-template argument deduction with parentheses: GCC vs. clang

问题描述

相关但(IMHO)不同:嵌套模板参数推论类模板不起作用

Related, but (IMHO) different: Nested template argument deduction for class templates not working

以下C ++ 17代码被GCC 8拒绝，但是clang对其进行编译没有任何问题.在出现问题的行之前，GCC的错误消息作为注释包含在内.

The following C++17 code is rejected from GCC 8, but clang compiles it without any issues. The GCC's error message is included as a comment just before the problematic line.

哪个编译器在这里正确?

Which compiler is correct here?

https://godbolt.org/z/WG6f7G

template<class T>
struct Foo {
    Foo(T) {}
};

template<class T>
struct Bar {
     Bar(T) {};
};

void works() {
    Bar bar{1};// {}
    Foo foo(bar);// ()
}

void works_too() {
    Foo foo{Bar{1}};// {{}}
}

void error_in_gcc() {
// error: 'auto' parameter not permitted in this context
    Foo foo(Bar{1});// ({})
}

void but_this_works() {
    Foo(Bar{1});// ({})
}

推荐答案

对此问题的评论指出这是GCC错误.它已归档为GCC错误报告 89062 .

Comments to this question state that this is a GCC bug. It has been filed as GCC bug report 89062.

这篇关于“嵌套"带括号的类模板参数推导:GCC与clang的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！