import

import  filename  [ , ... ] ;

filename

Specifies the name of the header or IDL file to import.

Examples

import "recycled.idl";   

import "system.h";

import  unknwn.idl ;

import "part1.idl", "part2.idl", "part3.idl";   

Remarks

The import directive specifies another .IDL file containing definitions you wish to reference from the main .IDL file. The imported file is processed separately from the main IDL file and the CPP preprocessor is invoked independently on this file. All resultant type, constant, and interface definitions are available to the main .IDL file. This implies that CPP directives like #define do not carry over from an imported IDL file to the main IDL file, and vice versa

IDL statements, such as const declarations, typedefs, and interfaces become available to the importing file.

Similar to the C-language preprocessor macro #include, the import directive directs the compiler to include data types defined in the imported IDL files. Unlike the #include directive, the import directive ignores procedure prototypes, since no stubs are generated for anything in the imported file.

The import keyword is optional and can appear zero or more times in the IDL file. Each import keyword can be associated with more than one file name. Separate multiple filenames with commas. You must enclose the file name within quotation marks and end the import statement with a semicolon (;). Note that an interface without attributes can be imported into a base IDL file. However, the interface must contain only datatypes with no procedures. If even one procedure is contained in the interface, a localF4C553 or UUIDWWSPKN attribute must be specified.

The C-language header (.H) file generated for the interface does not directly contain the imported types but instead generates a #include directive for the header file corresponding to the imported interface. For example, when FOO.IDL imports BAR.IDL, the generated header file FOO.H includes BAR.H (FOO.H contains the directive #include BAR.H).

The import function is idempotent   that is, importing an interface more than once has no effect.

The behavior of the import directive is independent of the MIDL compiler mode switches /osf, and /app_config. However, pointer attribute decoration across imports may depend on the compiler mode (/osv vs. the default, /ms_ext). For details see Pointer-Attribute Type Inheritance68Y._JS.

See Also