CMake/Help/command/math.rst

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math
----
Evaluate a mathematical expression.
.. code-block:: cmake
math(EXPR <variable> "<expression>" [OUTPUT_FORMAT <format>])
Evaluates a mathematical ``<expression>`` and sets ``<variable>`` to the
resulting value. The result of the expression must be representable as a
64-bit signed integer.
The mathematical expression must be given as a string (i.e. enclosed in
double quotation marks). An example is ``"5 * (10 + 13)"``.
Supported operators are ``+``, ``-``, ``*``, ``/``, ``%``, ``|``, ``&``,
``^``, ``~``, ``<<``, ``>>``, and ``(...)``; they have the same meaning
as in C code.
Hexadecimal numbers are recognized when prefixed with ``0x``, as in C code.
The result is formatted according to the option ``OUTPUT_FORMAT``,
where ``<format>`` is one of
``HEXADECIMAL``
Hexadecimal notation as in C code, i. e. starting with "0x".
``DECIMAL``
Decimal notation. Which is also used if no ``OUTPUT_FORMAT`` option
is specified.
For example
.. code-block:: cmake
math(EXPR value "100 * 0xA" OUTPUT_FORMAT DECIMAL) # value is set to "1000"
math(EXPR value "100 * 0xA" OUTPUT_FORMAT HEXADECIMAL) # value is set to "0x3e8"