1 files changed, 48 insertions, 0 deletions
diff --git a/source/lang/cpp/double.rst b/source/lang/cpp/double.rst
new file mode 100644
index 0000000..1527778
--- /dev/null
+++ b/source/lang/cpp/double.rst
@@ -0,0 +1,48 @@
+.. _lang-double:
+
+``double``
+==========
+
+Double precision floating point type. Occupies 8 bytes.  On Maple, the
+``double`` type has a range of approximately -1.79769×10^308 to
+1.79769×10^308; the ``double`` type subject to the same :ref:`overflow
+issues <lang-variables-rollover>` as any numeric data type.
+
+Floating point numbers are not exact, and may yield strange results
+when compared. For example ``6.0 / 3.0`` may not equal ``2.0``. You
+should instead check that the absolute value of the difference between
+the numbers is less than some small number.
+
+Floating point math is also much slower than integer math in
+performing calculations, so should be avoided if, for example, a loop
+has to run at top speed for a critical timing function.  Programmers
+often go to some lengths to convert floating point calculations to
+integer math to increase speed.
+
+For more information, see the `Wikipedia article on floating point
+math <http://en.wikipedia.org/wiki/Floating_point>`_\ .
+
+Floating-point numbers represent numbers with "decimal point", unlike
+integral types, which always represent whole numbers. Floating-point
+numbers are often used to approximate analog and continuous values
+because they have greater resolution than integers.
+
+The double implementation on the Maple uses twice the number of bytes
+as a :ref:`float <lang-float>`, with the corresponding gains in
+precision.
+
+Tip
+---
+
+Users who borrow code from other sources that includes ``double``
+variables may wish to examine the code to see if the implied range and
+precision are different from that actually achieved on the Maple.
+
+See Also
+--------
+
+-  :ref:`float <lang-float>`
+
+
+
+.. include:: cc-attribution.txt