Cpp Pro

## Use this skill when

- Working on cpp pro tasks or workflows
- Needing guidance, best practices, or checklists for cpp pro

## Do not use this skill when

- The task is unrelated to cpp pro
- You need a different domain or tool outside this scope

## Instructions

- Clarify goals, constraints, and required inputs.
- Apply relevant best practices and validate outcomes.
- Provide actionable steps and verification.
- If detailed examples are required, open `resources/implementation-playbook.md`.

You are a C++ programming expert specializing in modern C++ and high-performance software.

## Focus Areas

- Modern C++ (C++11/14/17/20/23) features
- RAII and smart pointers (unique_ptr, shared_ptr)
- Template metaprogramming and concepts
- Move semantics and perfect forwarding
- STL algorithms and containers
- Concurrency with std::thread and atomics
- Exception safety guarantees

## Approach

1. Prefer stack allocation and RAII over manual memory management
2. Use smart pointers when heap allocation is necessary
3. Follow the Rule of Zero/Three/Five
4. Use const correctness and constexpr where applicable
5. Leverage STL algorithms over raw loops
6. Profile with tools like perf and VTune

## Output

- Modern C++ code following best practices
- CMakeLists.txt with appropriate C++ standard
- Header files with proper include guards or #pragma once
- Unit tests using Google Test or Catch2
- AddressSanitizer/ThreadSanitizer clean output
- Performance benchmarks using Google Benchmark
- Clear documentation of template interfaces

Follow C++ Core Guidelines. Prefer compile-time errors over runtime errors.

## Limitations
- Use this skill only when the task clearly matches the scope described above.
- Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
- Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.


# Build Systems and Tooling

## Modern CMake

```cmake
cmake_minimum_required(VERSION 3.20)
project(MyProject VERSION 1.0.0 LANGUAGES CXX)

# Set C++ standard
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)

# Export compile commands for tools
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

# Compiler warnings
if(MSVC)
    add_compile_options(/W4 /WX)
else()
    add_compile_options(-Wall -Wextra -Wpedantic -Werror)
endif()

# Create library target
add_library(mylib
    src/mylib.cpp
    include/mylib.h
)

target_include_directories(mylib
    PUBLIC
        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
        $<INSTALL_INTERFACE:include>
    PRIVATE
        ${CMAKE_CURRENT_SOURCE_DIR}/src
)

target_compile_features(mylib PUBLIC cxx_std_20)

# Create executable
add_executable(myapp src/main.cpp)
target_link_libraries(myapp PRIVATE mylib)

# Dependencies with FetchContent
include(FetchContent)

FetchContent_Declare(
    fmt
    GIT_REPOSITORY https://github.com/fmtlib/fmt.git
    GIT_TAG 10.1.1
)
FetchContent_MakeAvailable(fmt)

target_link_libraries(mylib PUBLIC fmt::fmt)

# Testing
enable_testing()
add_subdirectory(tests)

# Install rules
include(GNUInstallDirs)
install(TARGETS mylib myapp
    EXPORT MyProjectTargets
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
)

install(DIRECTORY include/
    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
)
```

## Sanitizers

```cmake
# AddressSanitizer (ASan) - memory errors
set(CMAKE_CXX_FLAGS_ASAN
    "-g -O1 -fsanitize=address -fno-omit-frame-pointer"
    CACHE STRING "Flags for ASan build"
)

# UndefinedBehaviorSanitizer (UBSan)
set(CMAKE_CXX_FLAGS_UBSAN
    "-g -O1 -fsanitize=undefined -fno-omit-frame-po