在C++11中,引入了尾返回类型(trailing return type)的概念,允许在函数声明中使用 auto 关键字,并在参数列表之后使用 -> 符号来指定返回类型。这种语法在处理复杂的返回类型或依赖于函数参数的返回类型时特别有用。基本语法:auto functionName(parameters) -> returnType { // 函数体 }
在C++中,遇到错误消息 "error: 'auto' return without trailing return type; deduced return types are a C++14 extension" 时,表明编译器在尝试使用 auto 作为函数返回类型,但没有提供后置返回类型(trailing return type),这是C++14及其后续版本中的一个特性。下面是对该错误的详细解释和解决方案: 1. 错误消息...
template <typename MessageT> auto CreateWriter(const proto::RoleAttributes& role_attr) -> std::shared_ptr<Writer<MessageT>>;
Function max is using a trailing return type, which is equal to int max(int a, int b). This example shows a valid scenario of trailing return types, but it doesn't reflect the benefits of this feature. We can fully enjoy the convenience of generic programming by using trailing return ty...
The biggest difference between ordinary functions and functions using trailing return types is whether to postpose the return types. See the following example: auto max(int a, int b) -> int{} Function max is using a trailing return type, which is equal to int max(int a, int b). This...
f2(std::string);// 块作用域中的声明std::cout<<f2("bad12")<<'\n';}// 简单的非成员函数,返回 intintf1(){return42;}// 拥有异常说明和函数 try 块的函数intf2(std::string str)noexcepttry{returnstd::stoi(str);}catch(conststd::exception&e){std::cerr<<"stoi() failed!\n";return0;...
This is a well formed C++ code that uses trailing return type as a function type and pass it to std::function. It works well with GCC and Clang, but fails to compile with MSVC: #include <functional> #include <optional> using fn = std::function<auto(int*) -> std::opt...
On Compiler Explorer clang crashes when __PRETTY_FUNCTION__ appears in trailing return type. On my computer clang-cl.exe crashes when __FUNCSIG__ appears in trailing return type. Compiler Explorer, x64-64 clang (trunk), -std=c++26 -O2 -W...
example_wrap.cxx:248:34: error: ‘va_static_cast’ function uses ‘auto’ type specifier without trailing return type auto va_static_cast(PP &&... args) ^ example_wrap.cxx:248:34: note: deduced return type only available with -std=c++14 or -std=gnu++14 ...
function uses atuo type specifier without trailing return type 函数使用自动型无尾返回类型说明符