The C++20 standard states the following about source file inclusion:
15.3:5 (page 437):
The implementation shall provide unique mappings for sequences consisting of one or more nondigits or digits (5.10) followed by a period (.) and a single nondigit. The first character shall not be a digit. The implementation may ignore distinctions of alphabetical case.
Does this mean that including .hpp files is not guaranteed by the standard to be consistent?
Also does this mean that when a library relies on capitalization only to include the correct header, then it's an UB?