The std::is_nothrow_default_constructible template of C++ STL is present in the <type_traits> header file. The std::is_nothrow_default_constructible template of C++ STL is used to check whether the given type T is default constructible type or not and this is known for not to throw any exception. It return the boolean value true if T is default constructible type, Otherwise return false.
Header File:
#include<type_traits>
Template Class:
template <class T> struct is_nothrow_default_constructible;
Syntax:
std::is_nothrow_default_constructible::value
Parameters: The template std::is_nothrow_default_constructible accepts a single parameter T(Trait class) to check whether T is default constructible type or not.
Return Value: This template returns a boolean variable as shown below:
- True: If the type T is a is_nothrow_default_constructible.
- False: If the type T is not a is_nothrow_default_constructible.
Below is the program to illustrates the std::is_nothrow_default_constructible template in C/C++:
Program 1:
// C++ program to illustrate // std::is_nothrow_default_constructible #include <bits/stdc++.h> #include <type_traits> using namespace std;
// Declare structures struct X {
X( int , float ){};
}; struct Y {
Y( const Y&) {}
}; struct Z {
int n;
Z() = default ;
}; // Driver Code int main()
{ cout << boolalpha;
// Check if int is nothrow default
// constructible or not
cout << "int: "
<< is_nothrow_default_constructible< int >::value
<< endl;
// Check if struct X is nothrow default
// constructible or not
cout << "struct X: "
<< is_nothrow_default_constructible<X>::value
<< endl;
// Check if struct Y is nothrow default
// constructible or not
cout << "struct Y: "
<< is_nothrow_default_constructible<Y>::value
<< endl;
// Check if struct Z is nothrow default
// constructible or not
cout << "struct Z: "
<< is_nothrow_default_constructible<Z>::value
<< endl;
// Check if constructor X(int, float) is
// nothrow default constructible or not
cout << "constructor X(int, float): "
<< is_nothrow_default_constructible<X( int , float )>::value
<< endl;
return 0;
} |
int: true struct X: false struct Y: false struct Z: true constructor X(int, float): false
Reference: http://www.cplusplus.com/reference/type_traits/is_nothrow_default_constructible/