This units library strives to provide typesafe code for representing any kind of numerical unit (distance, volume, mass, etc) in C++ that are interoperable with the existing std::chrono implementation. Units strives to pure compile time where that is appropriate. In addition, use of user-defined literals are used to allow for more human-like representation of units.
auto distance = 1_m;
yieds:
units::distance<double> distance
Create a unit representing 2500 metres:
auto distance = 2500_m;
std::cout << distance.count() << std::endl; // 2500.0
Add 31 metres:
distance += 31_m;
std::cout << distance.count() << std::endl; // 2531.0
Convert to kilometres:
auto kilometres = units::distance_cast<units::kilometres>(distance);
std::cout << kilometres.count() << std::endl; // 2.531
Get fractional part of kilometres as metres:
auto metres = kilometres % 1_km;
std::cout << metres.count() << std::endl; // 531.0
Convert to feet:
auto feet = units::distance_cast<units::feet>(metres);
std::cout << feet.count() << std::endl; // 1742.13
Note that the default underlying type of the units class is double but you can easily change that yourself:
using metres_i = units::distance<int>;
metres_i foo{1234};
std::cout << foo.count() << std::endl; // 1234