Compiler Warning (Level 1) C4744
An external variable referenced or defined in two files has different types in those files. To resolve, either make the type definitions the same, or change variable name in one of the files.
C4744 is emitted only when files are compiled with /GL. For more information, see /GL (Whole Program Optimization).
C4744 usually occurs in C (not C++) files, because in C++ a variable name is decorated with type information. When the sample (below) is compiles as C++, you’ll get linker error LNK2019.