op

op is a small library that allows you to define mathematical operations for your types easily. It is very useful to quickly add operations to strong types:

struct Radians
    : public op::Addable<Radians>      // Defines Radians + Radians and Radians += Radians. This is much simpler than implementing these operators yourself, and less error-prone
    , public op::Scalable<Radians>     // Defines Radians * float, float * Radians, and Radians *= float
    , public op::Subtractable<Radians> // Defines Radians - Radians and Radians -= Radians
    , public op::Negatable<Radians>    // Defines -Radians
{
    float value
};

This is very modular because – depending on the semantics of your type – some operations might not make sense. For example you can't multiply Radians with Radians, but you can multiply Radians with scalars (floats and doubles).

Including

To add this library to your project, simply add these two lines to your CMakeLists.txt:

add_subdirectory(path/to/op)
target_link_libraries(${PROJECT_NAME} PRIVATE op::op)

Then include it as:

#include <op/op.hpp>

Usage

op is header-only! Simply #include <op/op.hpp> and you are good to go.

To add operations to your type it needs to inherit from the corresponding op class. Note that you need to pass your type as a template parameter to the op classes: this is the CRTP pattern.

Here are all the available operations:

struct MyStrongType
    : public op::Addable<MyStrongType>      // Defines MyStrongType + MyStrongType and MyStrongType += MyStrongType. This is much simpler than implementing these operators yourself, and less error-prone
    , public op::Subtractable<MyStrongType> // Defines MyStrongType - MyStrongType and MyStrongType -= MyStrongType
    , public op::Negatable<MyStrongType>    // Defines -MyStrongType
    , public op::Scalable<MyStrongType>     // Defines MyStrongType * float, float * MyStrongType, and MyStrongType *= float
    , public op::Multipliable<MyStrongType> // Defines MyStrongType * MyStrongType and MyStrongType *= MyStrongType
{
    float value
};

Running the tests

Simply use "tests/CMakeLists.txt" to generate a project, then run it.
If you are using VSCode and the CMake extension, this project already contains a .vscode/settings.json that will use the right CMakeLists.txt automatically.