static_assert(0 == std::rank_v); static_assert(0 == std::rank_v); static_assert(1 == std::...rank_v); static_assert(0 == std::rank_v); static_assert(1 == std::rank_v); static_assert...(1 == std::rank_v); static_assert(2 == std::rank_v); static_assert(2 == std::rank_v...); static_assert(3 == std::rank_v); 数组的维度,这玩意和向量的秩英文名一样啊。。
T.150: Check that a class matches a concept using static_assert T.150:用static_assert检查类和概念的匹配性 Reason...implementation file, let the compiler check the desired properties of X: 在某处,在实现文件中也可以,让编译器检查X的期望属性: static_assert...(Default_constructible); // error: X has no default constructor static_assert(Copyable);
image-20231213140920353 2.1 static_assert /** * static_assert - check integer constant expression at...build time * * static_assert() is a wrapper for the C11 _Static_assert, with a * little macro magic...__static_assert(expr, ##__VA_ARGS__, #expr) #define __static_assert(expr, msg, ...)..._Static_assert(expr, msg) 函数名称:static_assert 文件位置:include/linux/build_bug.h 函数解析:该宏定义主要用来 在编译时检查常量表达式...:表示编译失败后,要打印的错误信息 _Static_assert:C11中引入的关键字,用于判断表达式expr并打印错误信息msg。
#include #include static_assert(std::is_same_v); static_assert(typeid...(int) == typeid(int)); static_assert(typeid(int) == typeid(const int)); static_assert(not std::is_same_v...); static_assert(typeid(int) == typeid(const int&)); static_assert(not std::is_same_v
return false; } static_assert(not if_hell(false, false)); static_assert(not if_hell(false, true)); assert...(throws([]{ if_hell(true, false)); })); static_assert(if_hell(true, true)); [[nodiscard]] constexpr...return true; } static_assert(not if_heaven(false, false)); static_assert(not if_heaven(false, true))...; assert(throws([]{ if_heaven(true, false)); })); static_assert(if_heaven(true, true)); 别写if_hell这种面条
out_ptr and inout_ptr 帮助指示指针所有权 P1132 加上 ranges::starts_withand ranges::ends_with让string操作更流畅 P1659 让static_assert...= 0) if constexpr(flags & Flags::Exec) static_assert(bool(N)); static_assert(N); static_assert(N...= 0); static_assert(N % 4); Concurrency TS:又开始了, P1121 and P1122 hazard pointers read-copy-update...HasAButNotB); // as expected static_assert(HasAButNotB); // as expected static_assert(!...HasAButNotB); // as expected static_assert(HasAButNotB); // ...oops!
([]{ return std::integral; }.operator()()); struct f { auto foo() -> void; }; static_assert...(names_a_type); static_assert(!...names_a_type); template auto do_something() { static_assert(...(not fooable); struct foo1 { void foo(int, short); }; static_assert(fooable); struct foo2...{ void foo(int, auto); }; static_assert(fooable); 视频 C++ Weekly - Ep 319 - A JSON To C++ Converter
}; int f(int, short, float); static_assert(is_same_v); using Arg2Type...>::type; }; int f(int, short, float); static_assert(is_same_v::type, float>..., short, float)>::type, float>); static_assert(is_same_v...::type, float>); static_assert(is_same_v::type, float...>); static_assert(is_same_v::type, float>); static_assert
()); static_assert(month(11) == thanksgiving.month()); static_assert(day(25) == thanksgiving.day(...就是简单的接口用编译期测试来组合,尽可能constexpr,然后直接static_assert测试 #include #include #include <...(accumulate_string_digits("") == 0); static_assert(accumulate_string_digits("1") == 1); static_assert...(accumulate_string_digits("12345") == 15); static_assert(accumulate_string_digits("1a23c45c") == 15);...static_assert(accumulate_string_digits("Hello, World!")
= 'D') return false; } else { static_assert(true, "should not reach...= 'B') return; } else { static_assert(true, "should...= answers[9]) return; } else { static_assert(true...= 'D') return; } else { static_assert(true, "should...= 1) return; } else { static_assert(true, "should
InetAddress::InetAddress(uint16_t port, bool loopbackOnly, bool ipv6) { static_assert(offsetof(InetAddress..., addr6_) == 0, "addr6_ offset 0"); static_assert(offsetof(InetAddress, addr_) == 0, "addr_ offset...做了测试, static_assert(sizeof(InetAddress) == sizeof(struct sockaddr_in6), "InetAddress is...0"); static_assert(offsetof(sockaddr_in6, sin6_family) == 0, "sin6_family offset 0"); static_assert(...offsetof(sockaddr_in, sin_port) == 2, "sin_port offset 2"); static_assert(offsetof(sockaddr_in6, sin6
.> SetName(string name) && { static_assert(utils::pack<Tags......move(folderPath); return {move(m_data)}; } Configuration Build() && { static_assert...= -1, "'SetName' is mandatory"); static_assert(utils::pack); static_assert(std::totally_ordered); static_assert(std::totally_ordered...>); static_assert(not std::totally_ordered>)
// size: 4b => size: 8b // -------- // size: 8b }; static_assert...(12 == sizeof(unpacked)); static_assert(8 == sizeof(packed)); struct simple { int a; // size: 4b...(12 == sizeof(unpacked)); static_assert(not is_packed_layout_v); static_assert(8 == sizeof...(packed)); static_assert(is_packed_layout_v); static_assert(1 == sizeof(empty)); static_assert...(is_packed_layout_v); static_assert(4 == sizeof(simple)); static_assert(is_packed_layout_v<simple
#include #define FWD(x) std::forward(x) #define typed_static_assert(x) static_assert...auto additionnable2 = is_valid((x, y), x + y); constexpr auto has_meow = is_valid((x), x.meow()); static_assert...(additionnable1(a, b)); static_assert(!...additionnable1(a, c)); static_assert(additionnable1(c, c)); static_assert(!...additionnable2(c, a)); static_assert(has_meow(cat)); static_assert(!
1.4 static_assert关键字 static_assert关键字是c++11里面的静态断言,是在编译期断言,如果编译期不满足条件即报错; 因为是在编译期,所以要断言的必须是编译期能确定的值,不能是运行时才确定的值...; 例如: static_assert(sizeof(int) == 4); 1.6 std::function、std::bind封装可执行对象 std::bind和std::function是从
static_assert(-42 == -42z); static_assert(-42 == -42Z); static_assert(42 == 42uz); static_assert(42 =...= 42uZ); static_assert(42 == 42Uz); static_assert(42 == 42ZU); static_assert(42 == 42Zu); static_assert...operator\n"; return *this; } }; int main(){ MyData a, b; swap(a, b); static_assert...实现细节啥也没说 Cute C++ Tricks, Part 2 of N: More code you should learn from and never write constexpr里不能用static_assert
FUNCSIG__; } template static constexpr size_t hash() { static_assert...std::is_reference_v, "dont send references to hash"); static_assert(!...} #endif template static constexpr size_t hash() { static_assert...std::is_reference_v, "dont send references to hash"); static_assert(!
熟悉C++模板编程的小伙伴肯定第一时间想到通过SFINAE的方式来解决,让笔者来解决这个问题的话,会写出下面的代码: template T test(T a) { static_assert...std::is_same_v); static_assert(!...std::is_same_v); static_assert(!...std::is_same_v); static_assert(!...>); return a; } 这里写的代码是一个略微Trick的表达,利用decltype去获取操作符计算后的类型,然后用std::is_same_v进行一个其实没什么意义的类型比较,来满足static_assert
通用的初始化语法如下: template staticType ClassName::StaticVarName; 使用static_assert...语法如下: static_assert(expression being validated, "error message when check fails" 要禁止针对类型int实例化模板类,可使用...static_assert(),并将sizeof(T)与sizeof(int)进行比较,如果它们相等,就显示一条错误消息: static_assert(sizeof(T)!...template class everythingbutInt { public: everythingbutInt() { static_assert
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