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C++17 in Detail: A Deep Dive

The basics

Explore the fundamentals of std::variant in C++17 as a safer alternative to unions for type-safe data handling. Understand why unions should be avoided due to undefined behavior from strict aliasing rules, setting a foundation for using modern C++ features effectively.

We'll cover the following...

Unions are rarely used in the client code, and most of the time they should be avoided.

Floating point operations: An Example

C++
#include <iostream>
using namespace std;
union SuperFloat
{
  float f;
  int i;
};
int RawMantissa(SuperFloat f)
{
  return f.i & ((1 << 23) - 1);
}
int RawExponent(SuperFloat f)
{
  return (f.i >> 23) & 0xFF;
}

However, while the above code might ...