I’ve read this from cppreference.com:
Function-to-pointer conversion:
An lvalue of function type T can be implicitly converted to a prvalue pointer to that function. This does not apply to non-static member functions because lvalues that refer to non-static member functions do not exist.
Source: https://en.cppreference.com/w/cpp/language/implicit_conversion
What does ‘function type T’ here mean? does that mean a function with a return type T?
>Solution :
In programming languages like C++, a function type describes the signature of a function. Specifically, it tells you what type of arguments the function takes and what type of value it returns, i.e. it is signature of that function.
The T
serves to just give a name to that function type.
Think of
There always exist real number
X
that is larger than any given real number.
X
is that existing real number.
For your specific example:
In C++, an lvalue of function type can indeed be implicitly converted to a prvalue (pure rvalue) pointer to that function. Here’s a simple example to demonstrate this concept.
#include <iostream>
void foo(int x) {
std::cout << "Value of x: " << x << std::endl;
}
int main() {
// Both of these are valid:
void (*funcPtr1)(int) = &foo; // Explicitly using the address-of operator
void (*funcPtr2)(int) = foo; // Implicit conversion to pointer - What yours example is about
// Calling the function using the function pointers
funcPtr1(42); // Output: "Value of x: 42"
funcPtr2(43); // Output: "Value of x: 43"
return 0;
}