Editing C++ (section)

===Don't reinvent the wheel===

Before writing any general-purpose routine, look around and see if it exists in a standard library somewhere.  Besides saving yourself some trouble, standardized versions are typically more general, more efficient, and far less error-prone than your own custom solutions.  Some places to look:
* The C++ standard library
* The C++ STL (Standard Template) library (see http://www.cplusplus.com/reference/)
* boost (http://www.boost.org)
* LAPACK (for linear algebra routines)

If you're not familiar with boost, here is a description from its homepage:

"Boost provides free peer-reviewed portable C++ source libraries.

We emphasize libraries that work well with the C++ Standard Library. Boost libraries are intended to be widely useful, and usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use.

We aim to establish "existing practice" and provide reference implementations so that Boost libraries are suitable for eventual standardization. Ten Boost libraries are already included in the C++ Standards Committee's Library Technical Report (TR1) and will be in the new C++0x Standard now being finalized. C++0x will also include several more Boost libraries in addition to those from TR1. More Boost libraries are proposed for TR2.
"

Here are some areas where you should definitely NOT be writing you own custom tools:
* string manipulation
* platform-independent file path handling (use boost/filesystem)
* fixed-length integers (e.g 64 bit). See next section.
* parsing command line options and/or reading config files (use boost/program_options and/or boost/propertytree)