| Home | Libraries | People | FAQ | More

## Struct template make_dimension_list

boost::units::make_dimension_list

## Synopsis

    // In header: <boost/units/dimension.hpp>

    template<typename Seq>
    struct make_dimension_list {
      // types
      typedef unspecified type;
    };

## Description

Reduce dimension list to cardinal form. This algorithm collapses duplicate base dimension tags and sorts the resulting list by the tag ordinal value. Dimension lists that resolve to the same dimension are guaranteed to be represented by an identical type.

The argument should be an MPL forward sequence containing instances of the `dim` template.

The result is also an MPL forward sequence. It also supports the following metafunctions to allow use as a dimension.

- `mpl::plus` is defined only on two equal dimensions and returns the argument unchanged.

- `mpl::minus` is defined only for two equal dimensions and returns the argument unchanged.

- `mpl::negate` will return its argument unchanged.

- `mpl::times` is defined for any dimensions and adds corresponding exponents.

- `mpl::divides` is defined for any dimensions and subtracts the exponents of the right had argument from the corresponding exponents of the left had argument. Missing base dimension tags are assumed to have an exponent of zero.

- `static_power` takes a dimension and a static_rational and multiplies all the exponents of the dimension by the static_rational.

- `static_root` takes a dimension and a static_rational and divides all the exponents of the dimension by the static_rational.