Restrict passed parameter to a string literal

Question

I have a class to wrap string literals and calculate the size at compile time.

The constructor looks like this:

template< std::size_t N >
Liter         


        

Answer 1

A string literal does not have a separate type to distinguish it from a const char array.

This, however, will make it slightly harder to accidentally pass (non-const) char arrays.

#include 

struct Literal
{
    template< std::size_t N >
    Literal( const char (&literal)[N] ){}

    template< std::size_t N >
    Literal( char (&literal)[N] ) = delete;
};

int main()
{
    Literal greet( "Hello World!" );
    char a[] = "Hello world";
    Literal broke(a); //fails
}

As to runtime checking, the only problem with a non-literal is that it may not be null-terminated? As you know the size of the array, you can loop over it (preferable backwards) to see if there's a \0 in it.