In code generation, since the generated code is statically typed, the type of this.prop must be determined at code generation time.
When processing the first assignment to this.prop, it assigns its type as TFlag. Then when processing the second assignment, it produces the type mismatch error you observed, as FFlag is a different class type than TFlag.
It is possible to assign two distinct values with the same type, but different sizes. For example:
if runtimeCond
s = struct('f', 0); % 1x1 struct, field f = 1x1 double
this.prop = s;
else
s2 = struct('f', {1, 2}); % 1x2 struct array, field f = 1x1 double
this.prop = s2;
end
See also:
