class template
<type_traits>
std::is_nothrow_constructible
template <class T, class... Args> struct is_nothrow_constructible;
Is constructible throwing no exceptions
Trait class that identifies whether T is a constructible type using the set of argument types specified by Arg, and such construction is known not to throw any exception.
This class inherits from integral_constant as being either true_type or false_type.
Template parameters
- T
- A complete type, or void (possible cv-qualified), or an array of unknown bound.
- Args
- A list of complete types (or void, possibly cv-qualified, or an array of unknown bound) representing the argument types for the constructor form, in the same order as in the constructor.
If omitted, it checks whether the type is nothrow default-constructible.
Member constants
Inherited from integral_constant:
| member constant | definition |
|---|
| value | either true or false |
Example
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// is_nothrow_constructible example
#include <iostream>
#include <type_traits>
struct A { };
struct B {
B(){}
B(const A&) noexcept {}
};
int main() {
std::cout << std::boolalpha;
std::cout << "is_nothrow_constructible:" << std::endl;
std::cout << "int(): " << std::is_nothrow_constructible<int>::value << std::endl;
std::cout << "A(): " << std::is_nothrow_constructible<A>::value << std::endl;
std::cout << "B(): " << std::is_nothrow_constructible<B>::value << std::endl;
std::cout << "B(A): " << std::is_nothrow_constructible<B,A>::value << std::endl;
return 0;
}
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Output:
is_nothrow_constructible:
int(): true
A(): true
B(): false
B(A): true
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