D constrains integral types to specific sizes. But efficiency of different sizes varies from machine to machine, pointer sizes vary, and the maximum integer size varies. **stdint** offers a portable way of trading off size vs efficiency, in a manner compatible with the `stdint.h` definitions in C.

In the table below, the **exact alias**es are types of exactly the specified number of bits. The **at least alias**es are at least the specified number of bits large, and can be larger. The **fast alias**es are the fastest integral type supported by the processor that is at least as wide as the specified number of bits.

The aliases are:

Exact Alias | Description | At Least Alias | Description | Fast Alias | Description |
---|---|---|---|---|---|

int8_t | exactly 8 bits signed | int_least8_t | at least 8 bits signed | int_fast8_t | fast 8 bits signed |

uint8_t | exactly 8 bits unsigned | uint_least8_t | at least 8 bits unsigned | uint_fast8_t | fast 8 bits unsigned |

int16_t | exactly 16 bits signed | int_least16_t | at least 16 bits signed | int_fast16_t | fast 16 bits signed |

uint16_t | exactly 16 bits unsigned | uint_least16_t | at least 16 bits unsigned | uint_fast16_t | fast 16 bits unsigned |

int32_t | exactly 32 bits signed | int_least32_t | at least 32 bits signed | int_fast32_t | fast 32 bits signed |

uint32_t | exactly 32 bits unsigned | uint_least32_t | at least 32 bits unsigned | uint_fast32_t | fast 32 bits unsigned |

int64_t | exactly 64 bits signed | int_least64_t | at least 64 bits signed | int_fast64_t | fast 64 bits signed |

uint64_t | exactly 64 bits unsigned | uint_least64_t | at least 64 bits unsigned | uint_fast64_t | fast 64 bits unsigned |

The ptr aliases are integral types guaranteed to be large enough to hold a pointer without losing bits:

Alias | Description |
---|---|

intptr_t | signed integral type large enough to hold a pointer |

uintptr_t | unsigned integral type large enough to hold a pointer |

The max aliases are the largest integral types:

Alias | Description |
---|---|

intmax_t | the largest signed integral type |

uintmax_t | the largest unsigned integral type |

- License:
- Boost License 1.0.

- Authors:
- Walter Bright

- Source
- std/stdint.d

- public import
**core.stdc.stdint**;

© 1999–2019 The D Language Foundation

Licensed under the Boost License 1.0.

https://dlang.org/phobos/std_stdint.html