Coding Style and Idioms

Substance

Indexing Containers

For container indexes, use:

• size_t for std::vector<S>,

• int for Eigen::Matrix<S, R, C>, and

• T::size_type for template params T that might be instantiated as either a std::vector<S> or Eigen::Matrix<S, R, C>.

One could argue we should always use Eigen::Matrix<S, R, C>::size_type for Eigen constructs just in case we ever decide that we want to change their default indexing from int to something else. But int should be OK for now because if we change the index type for some reason, the compiler will let us find instances.

Style

No Tabs in Code

Use two spaces for indentation. There are emacs modes to enforce this.

80-character Lines

Whenever possible, keep lines to 80 characters or less. It makes it much easier to review pull requests, view diffs, etc.

Templates

For both template parameter lists and template argument lists, use spaces between parameters and arguments. As above for template argument lists:

Eigen::Matrix<S, R, C>::size_type

and for template parameter lists:

template<typename T1, typename T2>
struct foo {
...
};