simnalamburt / obj-rs

If we have an waveform file that has vertex indicies larger than the I number type that we supply it, we causing a panic, with no chance to potentially catch the error via an Err Result value. Should it return Err instead of hard panicking?

thread 'main' panicked at 'Unable to convert the index from usize', /home/user/.cargo/registry/src/index.crates.io-6f17d22bba15001f/obj-rs-0.7.1/src/lib.rs:277:30
stack backtrace:
   0: rust_begin_unwind
             at /rustc/8bdcc62cb0362869f0e7b43a6ae4f96b953d3cbc/library/std/src/panicking.rs:578:5
   1: core::panicking::panic_fmt
             at /rustc/8bdcc62cb0362869f0e7b43a6ae4f96b953d3cbc/library/core/src/panicking.rs:67:14
   2: core::panicking::panic_display
             at /rustc/8bdcc62cb0362869f0e7b43a6ae4f96b953d3cbc/library/core/src/panicking.rs:150:5
   3: core::panicking::panic_str
             at /rustc/8bdcc62cb0362869f0e7b43a6ae4f96b953d3cbc/library/core/src/panicking.rs:134:5
   4: core::option::expect_failed
             at /rustc/8bdcc62cb0362869f0e7b43a6ae4f96b953d3cbc/library/core/src/option.rs:1952:5
   5: core::option::Option<T>::expect
             at /rustc/8bdcc62cb0362869f0e7b43a6ae4f96b953d3cbc/library/core/src/option.rs:912:21
   6: <obj::TexturedVertex as obj::FromRawVertex<I>>::process::{{closure}}
             at /home/user/.cargo/registry/src/index.crates.io-6f17d22bba15001f/obj-rs-0.7.1/src/lib.rs:276:37
   7: <obj::TexturedVertex as obj::FromRawVertex<I>>::process
             at /home/user/.cargo/registry/src/index.crates.io-6f17d22bba15001f/obj-rs-0.7.1/src/lib.rs:294:52
   8: obj::Obj<V,I>::new
             at /home/user/.cargo/registry/src/index.crates.io-6f17d22bba15001f/obj-rs-0.7.1/src/lib.rs:71:13
   9: obj::load_obj
             at /home/user/.cargo/registry/src/index.crates.io-6f17d22bba15001f/obj-rs-0.7.1/src/lib.rs:52:5
  10: rust3d_test::main_with_err
             at ./src/main.rs:32:15
  11: rust3d_test::main
             at ./src/main.rs:40:11
  12: core::ops::function::FnOnce::call_once
             at /rustc/8bdcc62cb0362869f0e7b43a6ae4f96b953d3cbc/library/core/src/ops/function.rs:250:5

Err sounds good idea.

obj-rs/obj-rs/src/lib.rs

Lines 276 to 277 in 1ed79eb

    
           let index = I::from_usize(vb.len()) 
        
               .expect("Unable to convert the index from usize");

I'll accept PR regarding this.

	let index = I::from_usize(vb.len())
	.expect("Unable to convert the index from usize");

Should load_obj panic on indicies that exceed the bounds of I