# Inactive shader variable, either optimized out or simple absent from the program
#
# Returned by `GamnitProgram::uniforms` or `GamnitProgram::attributes` when
# the uniform has not been identified as active by the driver.
# Operations on instances of this class have no effects.
#
# Act as a compatibility when a program expect a uniform to exist even in
# a context where the driver's compiler may have optimized it out.
# You must be careful when receiving an `InactiveVariable` as it may also
# silence real program errors, such type in variable name.
abstract class InactiveVariable
	super ShaderVariable

	redef fun is_active do return false
end