I guess C++ template metaprogramming is the 9th level of hell then?
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Rust macros are definitely a thing
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The macro system is powerful and necessary. Rust generics are closer to templates but not overpowered and prone to abuse like C++
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They're not really anything like templates. They work with syntax trees and are part of the parser. The comparison to make is with C macros, although they aren't like those legacy macros at all but rather more sophisticated and sane Lisp-style macros for making specialized DSLs.
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The comparison for templates is with generics, which are implemented in a similar way but they require type class (trait) bounds specified for everything that's used, rather than expanding and pattern matching. There's not template meta-programming in the same sense as C++.
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There are also procedural macros (compiler plugins), which are usable for some pretty cool things:
github.com/sfackler/rust-
docs.rs/regex/0.1.46/r
The standard library's type-checked format! macro is implemented as one of those:
doc.rust-lang.org/std/macro.form
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Usage or implementation of macros? The usage is just macro!(tokens), and the syntax within it is determined by how the macro defines the DSL. Implementing macros is definitely not pretty for anything complex, as you're messing with a token tree rather than it being normal code.
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