Real-world examples of metaprogramming
Advanced metaprogramming can appear to be very academic, so in order to demonstrate its usefulness, let's look at some examples that not only demonstrate the syntax of metaprogramming, but how it can be used in practice.
Example 1: creating a generic safe cast function
- You might lose a value if casting to an integer type of a lower bit length.
- You might lose a value if casting a negative value to an unsigned integer.
- If casting from a pointer to any other integer than
uintptr_t, the correct address might become incorrect. This is because C++ only guarantees that
uintptr_tis the only integer type that can withhold an address.
- If casting from
float, the result might be
doublevalue is too large for
- If casting between pointers with a
static_cast(), we might get...