Compat.h File Reference

Small compatibility shims for older toolchains and older wxWidgets. More...

#include <thread>
#include <version>
#include <algorithm>
#include <ranges>
#include <wx/defs.h>

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Data Structures
struct	stop_token
struct	stop_source
class	jthread

Macros
#define	wxWARN_UNUSED
	Marks a class whose unused instances are a bug.

Functions
template<typename R , typename T >
constexpr bool	ranges::contains (R &&r, const T &value)

Detailed Description

Small compatibility shims for older toolchains and older wxWidgets.

wxMaxima targets C++20 but aims to keep building on toolchains a few years behind. This header provides minimal fall-backs for std features that may be missing there: std::jthread / std::stop_token / std::stop_source, and std::ranges::contains. These were historically carried in Version.h; they live here now because they have nothing to do with the version and are CMake-independent (so this header is a plain committed file, not generated).

It also carries the same kind of fall-back for wxWidgets macros that only exist in newer wxWidgets than the 3.0.5 we still support - currently wxWARN_UNUSED, see its documentation at the bottom of this file.

Macro Definition Documentation

wxWARN_UNUSED

#define wxWARN_UNUSED

Marks a class whose unused instances are a bug.

It expands to attribute((warn_unused)), which makes the compiler report a local variable of that type that is never used. Plain -Wunused-variable cannot do that on its own: as soon as a type has a non-trivial constructor or destructor the compiler must assume the object exists for its side effects, so it stops warning - which is exactly why a dead Style style; or MaximaTokenizer::Token token; can sit unnoticed.

wxWidgets defines it itself from 3.2.7 on. This no-op fallback keeps wxMaxima building against the older wxWidgets it still supports (3.0.5, see AGENTS.md).

The <wx/defs.h> include above the guard is load-bearing: without it this header could be reached first, define the macro empty, and then wxWidgets' own "#ifndef wxWARN_UNUSED" would decline to redefine it - silently turning the attribute off on the very compilers that support it.