The following steps will set up some environment variables for this session
```
export CC=/usr/bin/gcc-6 and
export CXX=/usr/bin/g++-6
```
The following steps will install the latest compiler from source
Download gcc 6.3.0 from https://gcc.gnu.org/mirrors.html I used the Japanese mirror as this is the closest location to me http://ftp.tsukuba.wide.ad.jp/software/gcc/releases/gcc-6.3.0/gcc-6.3.0.tar.gz
Build configurations for Visual Studio, GNU Make, Ninja, and Xcode can be created using [cmake](https://cmake.org/) v3.2+. A full list of cmake generators can be found [here](https://cmake.org/cmake/help/v3.0/manual/cmake-generators.7.html). A basic build would look like (starting in the root xlnt directory):
```bash
mkdir build
cd build
cmake ..
make -j8
```
The resulting shared (e.g. libxlnt.dylib) library would be found in the build/lib directory. Other cmake configuration options for xlnt can be found using "cmake -LH". These options include building a static library instead of shared and whether to build sample executables or not. An example of building a static library with an Xcode project:
```bash
mkdir build
cd build
cmake -D STATIC=ON -G Xcode ..
cmake --build .
cd bin && ./xlnt.test
```
*Note for Windows: cmake defaults to building a 32-bit library project. To build a 64-bit library, use the Win64 generator*