missing_concrete_instance.m:014: Error: abstract instance declaration for
missing_concrete_instance.m:014:   `missing_concrete_instance.foo(int)' has no
missing_concrete_instance.m:014:   corresponding concrete instance in the
missing_concrete_instance.m:014:   implementation.
missing_concrete_instance.m:018: Error: abstract instance declaration for
missing_concrete_instance.m:018:   `missing_concrete_instance.foo(float)' has
missing_concrete_instance.m:018:   no corresponding concrete instance in the
missing_concrete_instance.m:018:   implementation.