Re: [boost] Interest in a library for type-safe bitwise operations?

Am 2024-03-25 11:38, schrieb Andrey Semashev via Boost:

On 3/24/24 02:22, Tobias Loew via Boost wrote:

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Am 2024-03-23 15:07, schrieb Дмитрий Архипов via Boost:

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сб, 23 мар. 2024 г. в 15:52, Tobias Loew via Boost :

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Hi,

I would like to gauge interest in a library that makes the usage of flag-like enumerations safer. The library is called Boost.Flags, and its key features are ... Example on Godbolt: https://godbolt.org/z/qbojncnd7

From the reading of the docs I gathered that the library relies on operators in the global namespace, rather than using a macro to define operators in an enum's namespace. This has a certain flaw: https://godbolt.org/z/xePjK3es6

The described flaw can be avoided by either including flags.hpp before `foobar` or by `using ::operator |` in the enums namespace. (https://godbolt.org/z/rT5678n4f)

I could add a macro the enables ADL for the current namespace, e.g.

#define BOOST_FLAGS_ENABLE_ADL_FOR_NS  \ using ::operator| \ using ::operator& \ using ::operator^ \ ... and so on

I don't really like the idea of operators in the global namespace. I would rather prefer if the operators were defined in the library's namespace, and the enablement was always through the macro. Where the macro would not just import the operators for lookup but also "enable" them for the given enum.

The library now has a macro-option to prevent importing all operators into the global namespace (BOOST_FLAGS_NO_GLOBAL_USING). Additionally, there are macros to easily import all operators/utility functions into a namespace (BOOST_FLAGS_USING_OPERATORS(), BOOST_FLAGS_USING_UTILITIES()). I'm not sure what you mean by your last sentence. Do you just ask for a macro, like #define BOOST_FLAGS_ENABLE(Enum) \ constexpr inline bool boost_flags_enable(Enum) { return true; } \ BOOST_FLAGS_USING_OPERATORS() or something else?