has_trivial_copy Class

Tests if type has trivial copy constructor.

template<class Ty>
    struct has_trivial_copy;

Parameters

• Ty
  The type to query.

Remarks

An instance of the type predicate holds true if the type Ty is a class that has a trivial copy constructor, otherwise it holds false.

A copy constructor for a class Ty is trivial if:

it is implicitly declared

the class Ty has no virtual functions

the class Ty has no virtual bases

all the direct bases of the class Ty have trivial copy constructors

the classes of all the non-static data members of class type have trivial copy constructors

the classes of all the non-static data members of type array of class have trivial copy constructors

Example

 

// std_tr1__type_traits__has_trivial_copy.cpp 
// compile with: /EHsc 
#include <type_traits> 
#include <iostream> 
 
struct trivial 
    { 
    int val; 
    }; 
 
struct throws 
    { 
    throws() throw(int) 
        { 
        } 
 
    throws(const throws&) throw(int) 
        { 
        } 
 
    throws& operator=(const throws&) throw(int) 
        { 
        } 
 
    int val; 
    }; 
 
int main() 
    { 
    std::cout << "has_trivial_copy<trivial> == " << std::boolalpha 
        << std::has_trivial_copy<trivial>::value << std::endl; 
    std::cout << "has_trivial_copy<throws> == " << std::boolalpha 
        << std::has_trivial_copy<throws>::value << std::endl; 
 
    return (0); 
    } 
 

has_trivial_copy<trivial> == true
has_trivial_copy<throws> == false

Requirements

Header: <type_traits>

Namespace: std

See Also

Reference

<type_traits>

has_nothrow_copy Class