<cstdbool>
Includes the C standard library header <stdbool.h> and adds the associated names to the std namespace.
Note
Because the <stdbool.h> header defines macros that are keywords in C++, including it has no effect. The <stdbool.h> header is deprecated in C++. The <cstdbool> header is deprecated in C++17 and removed in the draft C++20 standard.
Requirements
Header: <cstdbool>
Namespace: std
Remarks
Including this header ensures that the names declared using external linkage in the C standard library header are declared in the std namespace.
See also
Header files reference
C++ standard library overview
Thread safety in the C++ standard library