Universal Function Call Syntax

Universal function call syntax (UFCS)

UFCS is a feature that is applied by the compiler automatically. It enables the member function syntax even for regular functions. It can be explained simply by comparing two expressions:

variable.foo(arguments)

When the compiler encounters an expression like the one above, if there is no member function named foo that can be called on a variable with the provided arguments, the compiler also tries to compile the following expression:

foo(variable, arguments)

If this new expression can be compiled, the compiler simply accepts that one. As a result, foo() gets accepted to be used by the member function syntax even ...