BrainStone / StaticMap

A compile time static map for C++20 or above

StaticMap

A compile time static map for C++20 or above.

This nifty little library offers the class static_map and the convenient alias static_string_map, which is a class that can store a key value mapping at compile time, including retrieving the values at compile time. The strings in question for static_string_map are std::string_view strings for maximum efficiency.

Usage Example

#include "static_string_map.hpp"

constexpr static_map messages = make_static_string_map({{"hi", "hi"}, {"foo", "bar"}});
constexpr std::string_view constexpr_message = messages["foo"]; // Initialized to "bar"
constexpr std::string_view constexpr_message = messages["xxx"]; // Compile error

int main() {
    std::string dynamic_message;
    std::cin >> dynamic_message
    
    std::cout << messages[dynamic_message] << std::endl; // Will either print the corresponding message or throw an exception
}

Using this lib

This is a CMake library, and you can use it as you would any other CMake library. See Instructions further down on how to use it without CMake too.

CMake

You can use the FetchContent module to let CMake download the lib for you:

# Download stomfoolery
include(FetchContent)
FetchContent_Declare(
        static_map
        GIT_REPOSITORY https://github.com/BrainStone/StaticMap.git
        GIT_TAG v2.0.0
)

FetchContent_MakeAvailable(static_map)

# Use static_map
project(${PROJECT_NAME} CXX)
target_link_libraries(${PROJECT_NAME} PRIVATE static_map)

Without CMake

Essentially you have two options:

• Add $static_map_base_path/src to your include paths.
• Copy src/static{,_string}_map.hpp into an already in use include path.

Building

First of all there's no actual library to build. The only thing that can be build and executed are the test.
Now this is a CMake project, so just follow standard build procedure:

# Build
cmake -B build
cmake --build build

# Run tests
cd build
ctest