The interface of C standard library is defined by the following collection of headers.
| Conditionally compiled macro that compares its argument to zero | |
| (since C99) | Complex number arithmetic |
| Functions to determine the type contained in character data | |
| Macros reporting error conditions | |
| (since C99) | Floating-point environment |
| Limits of floating-point types | |
| (since C99) | Format conversion of integer types |
| (since C95) | Alternative operator spellings |
| Ranges of integer types | |
| Localization utilities | |
| Common mathematics functions | |
| Nonlocal jumps | |
| Signal handling | |
| (since C11) | alignas and alignof convenience macros |
| Variable arguments | |
| (since C11) | Atomic operations |
| (since C23) | Macros to work with the byte and bit representations of types |
| (since C99) | Macros for boolean type |
| (since C23) | macros for performing checked integer arithmetic |
| Common macro definitions | |
| (since C99) | Fixed-width integer types |
| Input/output | |
| General utilities: memory management, program utilities, string conversions, random numbers, algorithms | |
| (since C11) | noreturn convenience macro |
| String handling | |
| (since C99) | Type-generic math (macros wrapping math.h and complex.h) |
| (since C11) | Thread library |
| Time/date utilities | |
| (since C11) | UTF-16 and UTF-32 character utilities |
| (since C95) | Extended multibyte and wide character utilities |
| (since C95) | Functions to determine the type contained in wide character data |
C++ documentation for C++ Standard Library header files