(1) Generate Visual Studio project using GN.
(2) Open solution in Visual Studio.
(3) Open any C++ file and start compiling it (select Compile option from Build menu).

Current result:
File is compiled successfully, but Visual Studio also produces a warning:

warning MSB8004: Output Directory does not end with a trailing slash.  This build instance will add the slash as it is required to allow proper evaluation of the Output Directory.