Utils/StringUtil: Fixes ltrim and adds a unittest

[Sonicadvance1]

ltrim had the issue that it would always consume the left-most character even if it wasn't whitespace. So FEXLoader would turn in to EXLoader, even without any whitespace in the string.

Adds a test to ensure this doesn't occur again.

[pmatos]

Nice - lgtm. :) We don't likely use this in any critical place; otherwise, I would wonder how anything works.

[pmatos]

Is there a reason we are not using std::erase_if from c++20, instead of erase+find_if? https://en.cppreference.com/w/cpp/string/basic_string/erase2

Or the equivalent using std::remove_if, if we need to use iterators.

[Sonicadvance1]

Is there a reason we are not using std::erase_if from c++20, instead of erase+find_if? https://en.cppreference.com/w/cpp/string/basic_string/erase2

Or the equivalent using std::remove_if, if we need to use iterators.

Haven't really looked at it, but I assume the predication would have different behaviour. I'm obviously not a very big C++ buff, using things for convenience rather than knowing every detail of it.

[pmatos]

Is there a reason we are not using std::erase_if from c++20, instead of erase+find_if? https://en.cppreference.com/w/cpp/string/basic_string/erase2 Or the equivalent using std::remove_if, if we need to use iterators.

Haven't really looked at it, but I assume the predication would have different behaviour. I'm obviously not a very big C++ buff, using things for convenience rather than knowing every detail of it.

Ah, actually I have tried it and it wouldn't work because erase_if would remove all white space instead of just trimming it, so it seems like your approach is the best unless you want to get into views and ranges etc. But it's simpler as you have it. Sorry for the noise.