const is an invalid WGSL keyword

[junglie85]

I'm trying to declare a constant value in a shader for the max size of several arrays, but get the following error:

thread 'main' panicked at 'wgpu error: Validation Error

Caused by:
    In Device::create_shader_module
      note: label = `geometry.shader_module`

Shader 'geometry.shader_module' parsing error: expected global item ('struct', 'let', 'var', 'type', ';', 'fn') or the end of the file, found 'const'
  ┌─ wgsl:3:1
  │
3 │ const max_size = 256;
  │ ^^^^^ expected global item ('struct', 'let', 'var', 'type', ';', 'fn') or the end of the file


    expected global item ('struct', 'let', 'var', 'type', ';', 'fn') or the end of the file, found 'const'

This is the abridged shader code that generates the error and attempted usage:

const max_size = 256;

@group(2) @binding(0) var<uniform> current_transform: array<Transform, max_size>;
@group(2) @binding(1) var<uniform> previous_transform: array<Transform, max_size>;

Am I missing something simple or is const support not yet implemented?

[teoxoy]

Use let. Rename to const will land as part of gfx-rs/naga#2075.

[junglie85]

Okay, thanks.

[gents83]

It should work now ☺️

[junglie85]

I shall update! Thanks 🙏