Can You Use Function Pointers with Built-in Operators in C ?

Can Built-in Standard Operators Have Function Pointers?

In C , you cannot directly refer to function pointers of built-in operators because they do not actually represent function objects. According to the C 11 standard, built-in operators are specifically designed for overload resolution and cannot be used for other purposes.

Overcoming the Limitation:

To work around this, you can use function objects defined in the standard library (§20.8). These function objects, such as equal_to for comparisons, decay to the equivalent operator in their operator() function. They can serve as valid arguments for function pointers.

Accessing Standard Class Operators:

While built-in operators are not directly accessible, you can utilize standard library operators as function pointers. However, you must specify the appropriate template instance to guide the compiler. For example, if you want to use the operator of std::basic_string, you would need to explicitly specify its template type as follows:

<code class="cpp">typedef std::basic_string<char> string_type;
...
std::cout << test_function<string_type>(a, b, &amp;std::operator+) << std::endl;</code>

Conclusion:

Although built-in operators cannot have direct function pointers due to their unique role, you can access their functionality through function objects provided by the standard library or by specifying the necessary template instances for standard class operators.

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