beman.elide: Implementation of Proposed std::elide

Implements: std::elide proposed in std::elide (P3288R3).

Status: Under development and not yet ready for production use.

Usage

std::elide is an object which:

• Wraps an invocable alongside the arguments thereto (by reference), and
• Implicitly converts to whatever that invocable yields

When combined with emplacement APIs this allows for the creation of instances of immovable types within storage managed by std::optional, std::list, et cetera.

Building beman.elide

Dependencies

This project has no C or C++ dependencies, however, it requires C++20 or above to compile.

Build-time dependencies:

• cmake
• ninja, make, or another CMake-supported build system
  • CMake defaults to "Unix Makefiles" on POSIX systems

How to build beman.elide

cmake --workflow --preset gcc-debug
cmake --workflow --preset gcc-release
cmake --install build/gcc-release --prefix /opt/beman.elide

Integrate beman.elide into your project

Use beman.elide directly from C++

If you want to use beman.elide from your project, you can include beman/elide/*.hpp files from your C++ source files

#include <beman/elide/elide.hpp>

# Assume /opt/beman.elide staging directory.
$ c++ -o identity_usage examples/identity_usage.cpp \
    -I /opt/beman.elide/include/

Use beman.elide directly from CMake

For CMake based projects, you will need to use the beman.elide CMake module to define the beman::elide CMake target:

find_package(beman.elide REQUIRED)

You will also need to add beman::elide to the link libraries of any libraries or executables that include beman/elide/*.hpp in their source or header file.

target_link_libraries(yourlib PUBLIC beman::elide)

Use beman.elide from other build systems

Build systems that support pkg-config by providing a beman.elide.pc file. Build systems that support interoperation via pkg-config should be able to detect beman.elide for you automatically.

Contributing

Issues and pull requests are appreciated.