Choose an indexer

The C/C++ search features use an index of symbols (from the source code in your projects, and from external header files) to find the locations of declarations and references. By default, the indexer is set to Fast, which means that it provides fastest indexing capabilities (for declarations and cross reference information). This is the recommended indexer.

To specify an indexer type for a project, open the project's Properties dialog, and then select C/C++ Indexer from the list on the left.

To specify an indexer type as the default indexer for new projects, choose Window > Preferences… , expand C/C++ in the list on the left, and then choose Indexer.

In either case, you have the following choices:

Full indexer (complete parse)
Parses your project in the same manner that a compiler does. It starts at each compilation unit and parses that file and all files that it includes. This provides the most accurate index information. For large projects using complex C++ code, this indexer can slow down the IDE.
Fast indexer (recommended)
Similar to the Full indexer, except it parses each header file included in a project only once. For example, if a header file is included by two compilation units, the parsing of the second unit reuses the results of parsing the first unit. This is similar to how precompiled headers work. The indexing of large projects using the Fast indexer uses fewer resources than the Full indexer, but the resulting index isn't quite as accurate.
No indexer (search features will not work correctly)
Disables indexing completely. This also disables much of the search functionality.
Currently, the indexer gathers information to identify overloaded operators, which means that indexing time may be longer, and the size of the index file will likely be larger. Therefore, to skip the collection of implicit references, select the Skip implicit references (e.g. overloaded operators) option from Window > Preferences > C/C++ > Indexer .