wgsl-rs transpiles a deliberately constrained subset of Rust to WGSL. The macro is additive : it never translates or rewrites user code. Constructs that cannot map cleanly to WGSL are rejected at compile time rather than approximated.
Structs (including generic and const-generic structs)
Enums with #[repr(u32)]
impl blocks (free functions in WGSL), including trait impls and generic trait impls on arraysFree functions
const itemslet and let mut bindingsif / else, while, loop, for, matchAll binary, unary, and compound assignment operators
Arrays
Generic functions and generic structs (monomorphized)
Const generic parameters (const N: usize / const N: u32) on functions, structs, impl blocks, and template entry points
Feature Reason Workaround
Trait definitions Traits are Rust-only; impls generate WGSL functions Use concrete types in function signatures Borrowing / refs WGSL has no borrow semantics Use the ptr! macro for pointer types Arbitrary imports Module mapping is glob-only Use use crate::module::*; Closures No closure capture model in WGSL Write named functions asyncNo async runtime on GPU — Dynamic dispatch No vtables in WGSL Use enums or monomorphization QSelf call syntax <[u32; 4]>::method() not yet supportedUse T::method() via monomorphization (#131)
Feature Supported? Notes
Structs Yes Including generic and const-generic Enums Yes Requires #[repr(u32)] impl blocksYes Become free WGSL functions Trait impls Yes Methods become mangled WGSL functions Generic array impls Yes impl<T: Trait> Trait for [T; N] (#133)Free functions Yes const itemsYes let / let mutYes if / elseYes whileYes loopYes forYes matchYes See non_literal_match_statement_patterns allow Binary operators Yes Unary operators Yes Compound assignments Yes Arrays Yes Generic functions Yes Monomorphized at macro time Generic structs Yes Monomorphized Const generics Yes u32/usize only, monomorphized or instantiatedTraits No Definitions are Rust-only; impls are supported Borrowing / references No Use ptr! macro Arbitrary imports No Glob only Closures No asyncNo Dynamic dispatch No QSelf call syntax No <[u32; 4]>::method() (#131)