# <cstdlib>

<head><title>&lt;cstdlib&gt;</title></head>

# `<cstdlib>`

* * *

Include the standard header **`<cstdlib>`**
to define the macros traditionally defined in the Standard C library header
[`<stdlib.h>`](https://docs.qualcomm.com/doc/80-N3040-23/topic/cpp_stdlib.html).
Including this header also ensures that the names declared
with external linkage in the Standard C library header
are declared in the
[`std`](https://docs.qualcomm.com/doc/80-N3040-23/topic/cpp_lib_cpp.html#std%20namespace) namespace.
In this [implementation](https://docs.qualcomm.com/doc/80-N3040-23/topic/cpp_index.html#implementation),
the names may or may not also be declared in the global namespace,
depending on the specific translation environment.

* * *

See also the
**[Table of Contents](https://docs.qualcomm.com/doc/80-N3040-23/topic/cpp_index.html#Table%20of%20Contents)** and the
**[Index](https://docs.qualcomm.com/doc/80-N3040-23/topic/_cpp_index.html)**.

*[Copyright](https://docs.qualcomm.com/doc/80-N3040-23/topic/cpp_crit_pjp.html) © 1992-2006by P.J. Plauger. All rights reserved.*

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Last Published: Oct 06, 2026

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