Can C-Style Strings Be Used as Template Arguments in C ?

Can C-Style Strings Be Template Arguments?

Your attempt to instantiate a template using a C-style string fails with an error due to the invalid use of a string literal as a template argument.

While C-style strings cannot directly serve as template arguments, there are alternative approaches:

Use a Pointer to a Constant String

One workaround is to use a pointer to a constant string as the template argument:

<code class="c++">template <char const *str>
struct X {
    const char *GetString() const {
        return str;
    }
};

char global_string[] = "String";

int main() {
    X<global_string> x;
    cout << x.GetString();
}

Update: String Literals as Template Arguments with C 11

With C 11 and later, it is possible to use string literals as template arguments by utilizing character packs:

<code class="c++">template <char ...c>
struct X {
    const char (*GetString)() {
        return [](char*... s) { return s; }(c...);
    }
};

int main() {
    X<"S", "t", "r", "i", "n", "g"> x;
    cout << x.GetString();
}</code>

The above is the detailed content of Can C-Style Strings Be Used as Template Arguments in C ?. For more information, please follow other related articles on the PHP Chinese website!