If you customize the assembler, then I think that the inline assembly can't support uniform syntax. The syntax required by an assembler is defined by the assemb

If you customize the assembler, then I think that the inline assembly can't support uniform syntax. The syntax required by an assembler is defined by the assembler, not some language trying to inline it. The true state of things might be even more complicated, with C++ and Rust compilers choosing to parse assembly. But if they do that, it is necessarily going to interfere with using all of the features of the underlying customizable assembler.