Question

Is it possible to create a modifiable string literal in C++? For example:

char* foo[] = {
    "foo",
    "foo"
};
char* afoo = foo[0];
afoo[2] = 'g'; // access violation

This produces an access violation because the “foo”s are allocated in read only memory (.rdata section I believe). Is there any way to force the “foo”s into writable memory (.data section)? Even via a pragma would be acceptable! (Visual Studio compiler)

I know I can do strdup and a number of other things to get around the problem, but I want to know specifically if I can do as I have asked. 🙂

Answer 1

You could create a multidimensional array of chars:

#include <iostream>

int main(int argc, char** argv)
{
    char foo[][4] = {
        "foo",
        "bar"
    };
    char* afoo = foo[0];
    afoo[2] = 'g';
    std::cout << afoo << std::endl;
}

More verbose way to define the array:

char foo[][4] = {
    {'f', 'o', 'o', '\0'},
    {'b', 'a', 'r', '\0'}
};