CEP-0043: Exported Methods and Generic Specializations¶

Summary¶

Catalyst should eventually decide whether inherent methods and selected generic specializations can be exported as external ABI symbols.

V1 @export(.c) is valid only on free function definitions with bodies.

Example¶

Possible future shape:

const Gain = struct {
  value: f32

  @export(.c)
  fn apply(self: *const Gain, input: f32) f32 {
    return input * self.value
  }
}

V1 users write an explicit free function wrapper with the desired C-safe signature.

Motivation¶

Exporting methods and specializations can make interop APIs more direct. It also needs explicit receiver lowering, symbol naming, specialization identity, and ABI validation.

Proposed Direction¶

The proposal should cover:

• receiver-explicit lowering for exported methods;
• naming and @link_name defaults;
• selecting generic specializations for export;
• ABI validation after specialization;
• generated header behavior;
• visibility and duplicate symbol diagnostics.

V1 Compatibility¶

V1 users write explicit free function wrappers for exported method-like or specialization-specific APIs.

Related Details¶

• C ABI Interop
• Structs and Methods
• Function Types and Pointers