The long keyword designates a 32-bit integer.
[ signed | unsigned ] long [ int ] declarator-list;
Specifies one or more standard C declarators, such as identifiers, pointer declarators, and array declarators. (Function declarators and bit-field declarations are not allowed in structures that are transmitted in remote procedure calls. These declarators are allowed in structures that are not transmitted.) Separate multiple declarators with commas.
The long keyword can be preceded by either the keyword signed or the keyword unsigned. The int keyword is optional and can be omitted. To the MIDL compiler, a long integer is signed by default and is synonymous with signed long int. On 32-bit platforms, long is synonymous with int.
The long integer type is one of the base types of the IDL language. The long integer type can appear as a type specifier in const declarations, typedef declarations, general declarations, and function declarators (as a function return–type specifier and as a parameter-type specifier). For the context in which type specifiers appear, see Interface Definition (IDL) File.