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c++moveexplicit

Application of C++ Explicit Constructor

I am newbie in C++ 11. I found this term of explicit constructor. However I did not find any good explanation on explicit constructor. Can you please explain in what scenario I should use explicit constructor?

Thank you in advance.

Solution

  • An explicit constructor is a function that does not get called in implicit type conversion.

    For example:

    class A {
   A( int a ) {}
};

void foo( A a ) {}

    Here is totally legal to call foo(1) or use any variable of type int or that can be implicitly converted to an int. This is not always desirable, as it would mean that A is convertible from an integer, instead of being defined with an integer. Adding the explicit would avoid the conversion and, hence, give you a compilation error.