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# `units` - Physical Units Library for C++

## Summary

`Units` is a compile-time enabled Modern C++ library that provides compile-time dimensional
analysis and unit/quantity manipulation. The basic idea and design heavily bases on
`std::chrono::duration` and extends it to work properly with many dimensions. 

Here is a small example of possible operations:

```cpp
// simple numeric operations
static_assert(10_km / 2 == 5_km);

// unit conversions
static_assert(1_h == 3600_s);
static_assert(1_km + 1_m == 1001_m);

// dimension conversions
static_assert(1_km / 1_s == 1000_mps);
static_assert(2_kmph * 2_h == 4_km);
static_assert(2_km / 2_kmph == 1_h);

static_assert(1000 / 1_s == 1_kHz);

static_assert(10_km / 5_km == 2);
```


## Repository structure

That repository contains the following independent `cmake`-based projects:
 - `./src` - header-only project for `units`
 - `.` - project used for development needs that wraps `./src` project together with
   usage examples and unit tests
 - `./test_package` - library installation and Conan package verification
 
Please note that the projects depend on `cmake` git submodule in the `./cmake/common`
subdirectory.


## Building, testing, and installation

For a detailed information on project compilation, testing and reuse please refer to
[doc/INSTALL.md](doc/INSTALL.md).


## Library design

`units` library design rationale and documentation can be found in
[doc/DESIGN.md](doc/DESIGN.md) 


## Release notes

- 0.1.0 May 18, 2019
  - Initial library release
  - Begin semantic versioning
  - The last version to work with gcc-8