Macro for declaring/implementing traits with fake associated consts (in stable Rust)
Currently very fragile in terms of syntax: does not support traits/impls with any kind of generic parameters (either lifetimes or types).
The same macro is used for declaring a trait with associated consts, implementing such a trait, and accessing the consts.
The syntax is the same as that proposed for associated consts, except that:
- all consts must be at the beginning of the trait/impl, before any functions
- const declarations end with a comma, instead of a semicolon (this is due to a limitation of the macro system -- a type followed by a semicolon is for some reason not parseable)
See the tests for example usage.
At the moment they are not consts at all -- they simply expand to static functions with the
same name as the declared const. You may therefore access the const by calling
Trait::CONST(), or (for future proofing, in case the macro implementation changes), call the
macro again to access the const, as guilty!(Trait::CONST).