std::bit_cast
is a powerful C++ feature introduced in C++20 that allows you to safely reinterpret-cast between types of the same size without invoking undefined behavior. However, it has one limitation โ it only works for types with the same size. But what if you need to perform type conversions between types of different sizes? This is where our utility header comes into play.
When working with different-sized data types, the common approach is to use reinterpret_cast
, which can lead to undefined behavior in some cases. This method is neither safe nor portable, making it a potential source of bugs and compatibility issues.
We have created a small utility header file that extends the capabilities of std::bit_cast
. Our solution allows you to use bit_cast
for almost any type, ensuring safety and avoiding undefined behavior.
Consider the following example where you want to reinterpret-cast a float
to a uint64_t
:
float fx = 5.235;
// Old way with reinterpret_cast (unsafe)
auto ux = static_cast<uint64_t>(*reinterpret_cast<uint32_t*>(&fx));
// New way with our utility header (safe)
auto bx = bits::bit_cast<uint64_t>(fx);
With our utility header, you can perform this type conversion safely and efficiently without worrying about undefined behavior.
-
Safety: Our
bit_cast
extension ensures that you can safely reinterpret-cast between types of different sizes, reducing the risk of undefined behavior in your code. -
Constexpr:
bit_cast
is marked asconstexpr
, allowing you to use it in compile-time expressions.
To get started, simply include our utility header in your project:
cd safe_hash_source_dir
mkdir build
cmake ..
sudo make install
#include "safe_cast/safe_cast.h"
Now, you can use bits::bit_cast
to perform safe type conversions between different-sized types.
We welcome contributions from the community to improve and expand this utility. If you have any ideas, bug reports, or feature requests, please feel free to open an issue or submit a pull request.
This utility is provided under the APACHE License, so you are free to use it in your projects and contribute to its development.