类模板
<type_traits>
std::is_nothrow_copy_assignable
template <class T> struct is_nothrow_copy_assignable;
Is copy assignable throwing no exceptions
模板参数
- T
- 一个完整类型，或者void（可能带 cv 限定），或者一个未知边界的数组。
示例
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// is_nothrow_copy_assignable example
#include <iostream>
#include <type_traits>
struct A { };
struct B { B& operator= (const B&) {return *this;} };
struct C { C& operator= (const C&) noexcept {return *this;} };
int main() {
std::cout << std::boolalpha;
std::cout << "is_nothrow_copy_assignable:" << std::endl;
std::cout << "int: " << std::is_nothrow_copy_assignable<int>::value << std::endl;
std::cout << "A: " << std::is_nothrow_copy_assignable<A>::value << std::endl;
std::cout << "B: " << std::is_nothrow_copy_assignable<B>::value << std::endl;
std::cout << "C: " << std::is_nothrow_copy_assignable<C>::value << std::endl;
return 0;
}
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输出
is_nothrow_copy_assignable:
int: true
A: true
B: false
C: true
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