Enforcing const methods?

In the spirit of functional programming and easy reasoning about code, I'm a big fan of marking as much as possible with `const`.

I noticed that almost none of the GLTF methods are const. For example, `TransformMatrix::isIdentity()` is non-const, although it clearly must be. This means that in my own classes, when I have a `const TransformMatrix` variable, I now either have to make a copy, or mark it non-const.

What is your opinion about `const`?

Thanks,
Peter Verswyvelen

Start by reviewing the existing GLTF methods, especially TransformMatrix::isIdentity(), and inspect the one existing comment for any maintainer decision about const usage. Define which methods can safely be const and the scope of a consistent change; done means the project has an agreed policy and the applicable methods follow it.

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