build failure in tbb/task.h

[bartman]

simple cmake

# CMake file for a C++ program
cmake_minimum_required(VERSION 4.0)
project(work_contract_test VERSION 1.0 LANGUAGES CXX)

# create compile_commands.json
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
#set(CMAKE_CXX_EXTENSIONS OFF)

# https://github.com/buildingcpp/work_contract
include(FetchContent)
FetchContent_Declare(
    work_contract
    #GIT_REPOSITORY https://github.com/buildingcpp/work_contract.git
    GIT_REPOSITORY https://github.com/bartman/work_contract.git
    GIT_TAG        origin/main
)
FetchContent_MakeAvailable(work_contract)

# include pthread
find_package(Threads REQUIRED)

# build main.cpp
add_executable(mytest main.cpp)

# use pthread and work_contract libraries
target_link_libraries(mytest PRIVATE Threads::Threads work_contract)

using the first example

#include <library/work_contract.h>
#include <iostream>
#include <thread>

int main()
{
    // Create a work contract group
    bcpp::work_contract_group group;

    // Start worker thread to process scheduled work contracts
    std::jthread worker([&group](auto stopToken)
            {
                while (not stopToken.stop_requested())
                    group.execute_next_contract();
            });

    // Create a work contract from the work contract group
    auto contract = group.create_contract([]()
            {
                std::cout << "Hello, World! from Work Contract\n";
                bcpp::this_contract::release(); // Release to async destroy this contract
            });

    // Schedule the contract
    contract.schedule();

    // Main thread waits for contract to be released
    while (contract.is_valid()) {}

    // Signal worker to stop
    worker.request_stop();
    worker.join();

    return 0;
}

cmake -S. -Bbuild reports...

-- The CXX compiler identification is Clang 21.1.7
-- The C compiler identification is Clang 21.1.7
...
-- url: https://github.com/fmtlib/fmt.git
-- tag: main
-- {fmt} version: 12.1.1
...
-- url: https://github.com/wjakob/tbb.git
-- tag: master
...
-- url: https://github.com/google/googletest.git
-- tag: main
...
-- TBB: NOT using libc++.

cmake --build build fails with...

arning: unknown warning option '-Wno-changes-meaning' [-Wunknown-warning-option]
In file included from /home/bart/proj/snippets/work_contracts/build/tbb-src/src/old/concurrent_vector_v2.cpp:20:
/home/bart/proj/snippets/work_contracts/build/tbb-src/include/tbb/task.h:590:28: error: in-class initializer for static data member is not a constant expression
  590 |     static const kind_type binding_completed = kind_type(bound+1);
      |                            ^                   ~~~~~~~~~~~~~~~~~~
/home/bart/proj/snippets/work_contracts/build/tbb-src/include/tbb/task.h:590:48: note: integer value 2 is outside the valid range of values [0, 1] for the enumeration type 'kind_type'
  590 |     static const kind_type binding_completed = kind_type(bound+1);
      |                                                ^
1 warning and 1 error generated.
make[2]: *** [tbb-build/CMakeFiles/tbb_static.dir/build.make:93: tbb-build/CMakeFiles/tbb_static.dir/src/old/concurrent_vector_v2.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:1024: tbb-build/CMakeFiles/tbb_static.dir/all] Error 2
make: *** [Makefile:156: all] Error 2

I'm guessing this is a gcc vs clang thing.