而最接近的std::visit又缺少编译器的优化支持,所以在c++17中std::variant并不好用,跟Rust和函数式语言中出神入化的Sum Type还相去甚远,但是已经有许多围绕std::variant的提案被提交给c++委员会探讨,包括模式匹配,std::expected等等。
module;#include<expected>exportmoduleB;importA;exportstd::expected<int,int>bar(){returnfoo(); } example.cpp importB;intmain(){if(autor =bar()) {return*r; }else{returnr.error(); } } I get the following error: [4/6] ...
1、cmake .. PS D:\work\modern_cpp_work\ModernCpp\codes\std\expected\01\build> cmake .. -- Building for: Visual Studio 17 2022 -- Selecting Windows SDK version 10.0.19041.0 to target Windows 10.0.22621. -- The C compiler identification is MSVC 19.38.33130.0 -- The CXX compiler identi...
to be undefined behaviour. In this implementation it causes an assertion failure. The implementation of assertions can be overridden by defining the macroTL_ASSERT(boolean_condition)before #including <tl/expected.hpp>; by default,assert(boolean_condition)from the<cassert>header is used. Note that ...
QCOMPARE(m_returnMessages.count(), m_expectedMessages); for (const KDSoapMessage &response : qAsConst(m_returnMessages)) { for (const KDSoapMessage &response : std::as_const(m_returnMessages)) { QCOMPARE(response.childValues().first().value().toString(), expectedCountry());...
▶ execution (C++17 起) exit() exp() exp<>() (std::complex) exp<>() (std::valarray) exp2() (C++11 起) exp2f() (C++11 起) exp2l() (C++11 起) expf() (C++11 起) expected<> (C++23 起) expint() (C++17 起) expintf() (C++17 起) expintl() (C++17 起) expl() ...
We are using __builtin_LINE() function in Visual Studio 2019 to report the lines. This is working as expected when std=c++17. But when we use Visual Studio 2022 (17.7 and 17.8 preview 1) this function is reporting wrong lines when std=c++17 and working as expected when ...
C++11 标志着现代 C++的开端，C++14 在 11 的基础上查缺补漏，并未加入许多新特性，而 C++17 作为...
Now, after the changes, the code works as expected. Of course, it’s not always possible to change code like that. In many cases, you don’t want a copy. One place where I can see this might be callbacks for UI events. For QT I’ve seen code like this: QPushButton* button = ...
expected=1; } };voidConsumer() {while(flag.load(std::memory_order_acquire) <2);if(data[0] !=42) {//绝不会执行std::cout <<"False..."<<std::endl; }else{ std::cout<<"True..."<<std::endl; }return; }intmain() {