I tried supporting things like

function bar() {
	$absolute = '\A';
	$relative = 'A';

	assertType('class-string', ltrim($absolute, '\\'));
	assertType('class-string', ltrim($relative, '\\'));
}

but from the extension point of view these strings seem not to be class-strings...?

ConstantStringType::isClassString() is just a hint whether the string was created from ::class, so that we don't trigger the autoloading for irrelevant strings, which upsets some custom autoloaders.

So you don't need to do anything about it.

ConstantStringType::isClassString() is just a hint whether the string was created from ::class, so that we don't trigger the autoloading for irrelevant strings, which upsets some custom autoloaders.