# Release notes

- **0.8.0 WIP**
  - (!) refactor: `common_quantity`, `common_quantity_for`, `common_quantity_point`, `common_quantity_kind`, and `common_quantity_point_kind` removed
  - (!) refactor: `named_derived_unit` removed as it was not used
  - (!) refactor: `derived_unit` renamed to `derived_scaled_unit`
  - (!) refactor: `unit` renamed to `derived_unit`
  - (!) refactor: `U::is_named` removed from the unit types and replaced with `NamedUnit` concept
  - (!) refactor: `PrefixFamily` support removed
  - (!) refactor: `mi(naut)` renamed to `nmi`
  - (!) refactor: `knot` unit helper renamed to `kn` in FPS
  - (!) refactor: `knot` text symbol changed from `"knot"` to `"kn"`
  - refactor: `quantity` `op+()` and `op-()` reimplemented in terms of `reference` rather then `quantity` types
  - refactor(example): `glide_computer` now use dimensionless quantities with `ranged_representation` as `rep`
  - feat: HEP system support added (thanks [@RalphSteinhagen](https://github.com/RalphSteinhagen))
  - feat: `floor()`, `ceil()`, and `round()` support added (thanks [@hofbi](https://github.com/hofbi))
  - feat: `std::format` support for compliant compilers added
  - feat: conversion helpers from `mp-units` to `std::chrono` types added
  - feat: math functions can now be safely used with user-defined types
  - feat: conversion from `quantity_point` to `std::chrono::time_point` added
  - feat: `nautical_mile_per_hour` and `knot` added to `si::international` system
  - (!) fix: add `quantity_point::origin`, like `std::chrono::time_point::clock`
  - fix: enable any prefixes for most of the named units (beside those that use prefixes already)
  - fix: `hectare` definition fixed to be a prefixed version of `are` + other units
  - fix: account for different dimensions in `quantity_point_cast`'s constraint
  - fix: output stream operator now properly handles state
  - fix: `fmt` algorithms were overconstrained with `forward_iterator`
  - fix: CTAD for aliases fixed
  - fix: `derived_ratio` calculation
  - fix: `fill_t` assignment operator fixed
  - fix: improve downcast mode off
  - fix: `radioactivity` header compilation fixed
  - fix: `si::hep::dim_momentum` duplicated definition fixed
  - fix: `fps` can now coexist with `international` system
  - fix: public headers fixed to be standalone
  - test: standalone public headers tests added
  - (!) build: CMake generator in Conan is no longer obtained from an environment variable
  - (!) build: Required Conan version bumped to 1.48
  - (!) build: Conan 1.48 does not set `CMAKE_BUILD_TYPE` in the `conan_toolchain.cmake` anymore
  - build: AppleClang 13 support added (thanks [@fdischner](https://github.com/fdischner))
  - build: most of the `conanfile.py` refactored to be Conan 2.0 ready
  - build: `validate()` replaced with `configure()` to raise errors during `conan install` in Conan 1.X
  - build: minimum Conan version changed to 1.40
  - build: `linear-algebra` Conan repo is no needed anymore
  - build: Gitpod support added
  - build: clang-format-15 support added
  - build: export config to local build (#322)
  - build: fix export name of `mp-units-system`
  - build: fmt updated to 8.0.1
  - build: gsl-lite updated to 0.40.0
  - build: catch2 updated to 2.13.9
  - build: doxygen updated to 1.9.4
  - build: linear_algebra/0.7.0 switched to wg21-linear_algebra/0.7.2
  - ci: VS2022, gcc-11, clang-13, clang-14, and AppleClang 13 support added
  - ci: pre-commit support added (thanks [@hofbi](https://github.com/hofbi))
  - docs: Project documentation updated
  - docs: `CITATION.cff` file added
  - docs: `CONTRIBUTING.md` updated

- **0.7.0 May 11, 2021**
  - (!) refactor: `ScalableNumber` renamed to `Representation`
  - (!) refactor: output stream operators moved to the `units/quantity_io.h` header file
  - (!) refactor: Refactored the library file tree
  - (!) refactor: `quantity::count()` renamed to `quantity::number()`
  - (!) refactor: `data` system renamed to `isq::iec80000` (quantity names renamed too)
  - (!) refactor: `*deduced_unit` renamed to `*derived_unit`
  - (!) refactor: got rid of a `noble_derived_unit`
  - refactor: quantity (kind) point updated to reflect latest changes to `quantity`
  - refactor: basic concepts, `quantity` and `quantity_cast` refactored
  - refactor: `abs()` definition refactored to be more explicit about the return type
  - feat: quantity (point) kind support added (thanks [@johelegp](https://github.com/johelegp))
  - feat: quantity references support added (thanks [@johelegp](https://github.com/johelegp))
  - feat: quantity aliases support addded
  - feat: interoperability with `std::chrono::duration` and other units libraries
  - feat: CTAD for dimensionless quantity added
  - feat: `modulation_rate` support added (thanks [@go2sh](https://github.com/go2sh))
  - feat: SI prefixes for `isq::iec80000` support added (thanks [@go2sh](https://github.com/go2sh))
  - feat: a possibility to disable quantity UDLs support with `UNITS_NO_LITERALS` preprocessor define
  - feat: a support to define ISQ derived dimensions in terms of different number or order of components
  - perf: preconditions check do not influence the runtime performance of a Release build
  - perf: `quantity_cast()` generates less assembly instructions
  - perf: temporary string creation removed from `quantity::op<<()`
  - perf: value initialization for quantity value removed (left with a default initialization)
  - perf: limited the `equivalent` trait usage
  - perf: limited the C++ Standard Library headers usage
  - perf: rvalue references support added for constructors and getters
  - (!) fix: `exp()` has sense only for dimensionless quantities
  - (!) fix: `dim_torque` now properly divides by an angle (instead of multiply) + default unit name change
  - fix: quantity's operators fixed to behave like the underlying types do
  - fix: `quantity_cast()` fixed to work correctly with representation types not convertible from `std::intmax_t`
  - fix: ambiguous case for empty type list resolved
  - fix: downcasting facility for non-default-constructible types
  - fix: restore user-warnings within the library implementation
  - fix: the text symbol of `foot_pound_force` and `foot_pound_force_per_second`
  - fix: quantity modulo arithmetics fixed
  - (!) build: Conan testing version is now hosted on [Artifactory](https://mpusz.jfrog.io/ui/packages/conan:%2F%2Fmp-units)
  - (!) build: Linear Algebra is now hosted on its [Artifactory](https://twonington.jfrog.io/artifactory/api/conan/conan-oss)
  - (!) build: `BUILD_DOCS` CMake option renamed to `UNITS_BUILD_DOCS`
  - build: doxygen updated to 1.8.20
  - build: catch2 updated to 2.13.4
  - build: fmt updated to 7.1.3
  - build: ms-gsl replaced with gsl-lite/0.38.0
  - build: Conan generator switched to `cmake_find_package_multi`
  - build: Conan CMakeToolchain support added
  - build: CMake scripts cleanup
  - build: ccache support added
  - ci: CI switched from Travis CI to GitHub Actions

- **0.6.0 September 13, 2020**
  - feat: `quantity_point` support added (thanks [@johelegp](https://github.com/johelegp))
  - feat: Added angle as SI base dimension (thanks [@kwikius](https://github.com/kwikius))
  - feat: `si::angular_velocity` support added (thanks [@mikeford3](https://github.com/mikeford3))
  - feat: FPS system added (thanks [@mikeford3](https://github.com/mikeford3))
  - feat: Added support for mathematical function `exp(quantity)`
  - feat: Localization support for text output added (thanks [@rbrugo](https://github.com/rbrugo))
  - feat: Added STL random number distribution wrappers (thanks [@yasamoka](https://github.com/yasamoka))
  - (!) refactor: Refactored and cleaned up the library file tree
  - (!) refactor: `q_*` UDL renamed to `_q_*`
  - (!) refactor: UDLs with "per" in name renamed from `*p*` to `*_per_*`
  - (!) refactor: `ratio` changed to the NTTP kind
  - (!) refactor: `exp` and `Exp` renamed to `exponent` and `Exponent`
  - (!) refactor: `Scalar` concept renamed to `ScalableNumber`
  - (!) refactor: Dimensionless quantities redesigned to be of a `quantity` type
  - refactor: `math.h` function signatures refactored to use a `Quantity` concept (thanks [@kwikius](https://github.com/kwikius))
  - refactor: `[[nodiscard]]` added to many functions
  - fix: `si::day` unit symbol fixed to `d` (thanks [@komputerwiz](https://github.com/komputerwiz))
  - fix: `si::mole` unit symbol fixed to `mol` (thanks [@mikeford3](https://github.com/mikeford3))
  - (!) build: gcc-9 is no longer supported (at least gcc-10 is required)
  - build: Visual Studio 16.7 support added
  - build: linear_algebra updated to 0.7.0/stable
  - build: fmt updated to 7.0.3
  - build: range-v3 updated to 0.11.0
  - build: catch2 updated to 2.13.0
  - build: doxygen updated to 1.8.18
  - build: ms-gsl 3.1.0 dependency added
  - build: Removed the dependency on a git submodule with common CMake scripts

- **0.5.0 May 17, 2020**
  - Major refactoring and rewrite of the library
  - Units are now independent from dimensions
  - Dimensions now depend on units (base or coherent units are provided in a class template)
  - Quantity gets a Dimension template parameter again (as unit does not provide information about
    its dimension anymore)
  - Spaceship operator support added
  - Added official CGS system support
  - Added official data information system support
  - Repository file tree cleanup
  - `ratio` refactored to contain `Exp` template parameter (thanks a lot [@oschonrock](https://github.com/oschonrock)!)
  - SI fundamental constants added
  - `q_` prefix applied to all the UDLs (thanks [@kwikius](https://github.com/kwikius))
  - `unknown_unit` renamed to `unknown_coherent_unit`
  - Project documentation greatly extended and switched to Sphinx
  - A few more usage examples added
  - ASCII-only output support added (thanks [@yasamoka](https://github.com/yasamoka))
  - Representation values formatting extended (thanks [@rbrugo](https://github.com/rbrugo))
  - Output streams formatting support added
  - Linear algebra from `std::experimental::math` support added
  - Named SI units and their dimensions added (thanks [@rbrugo](https://github.com/rbrugo)
  - libfmt updated to 6.2.0
  - Added absolute functions and epsilon to math.h (thanks [@mikeford3](https://github.com/mikeford3))
  - Added a lot of prefixes to named units and introduced `alias_unit` (thanks [@yasamoka](https://github.com/yasamoka))
  - Linking with Conan targets only when they exists ([#98](https://github.com/mpusz/units/issues/98))
  - All physical dimensions and units put into `physical` namespace
  - CMake improvements
  - Velocity renamed to speed

  Many thanks to GitHub users [@oschonrock](https://github.com/oschonrock),
  [@kwikius](https://github.com/kwikius), and [@i-ky](https://github.com/i-ky) for their support
  in drafting a new library design.

- **0.4.0 Nov 17, 2019**
  - Support for derived dimensions in `exp` added
  - Added `pow()` and `sqrt()` operations on quantities
  - `units` removed from a `std::experimental` namespace
  - Downcasting facility refactored so the user does not have to write the boilerplate code anymore
  - From now on base dimensions should inherit from `base_dimension` class template
  - Added unit symbols definitions to `base_dimension` and derived units
  - Added support for `operator<<` on `quantity`
  - `fmt` support added
  - Derived unit factory helpers refactored
  - Refactored the way prefixed units are defined

- **0.3.1 Sep 18, 2019**
  - cmcstl2 dependency changed to range-v3 0.9.1

- **0.3.0 Sep 16, 2019 (CppCon 2019 design)**
  - The design as described on CppCon 2019 talk (<https://youtu.be/0YW6yxkdhlU>)
  - Applied the feedback from the Cologne evening session
    - `upcasting_traits` renamed to `downcasting_traits`
    - `Dimension` template parameter removed from quantity
  - `units` moved to a `std::experimental` namespace
  - Leading underscore prefix removed from UDLs
  - Added a few more derived dimensions
  - `meter` renamed to `metre`
  - Missing `operator*` added
  - Predefined dimensions moved to a dedicated directory
  - `dimension_` prefix removed from names of derived dimensions
  - cmcstl2 library updated to 2019.09.19
  - `base_dimension` is a value provided as `const&` to the `exp` type
  - integrated with Compiler Explorer
  - gsl-lite dependency removed
  - Fractional dimension exponents support added
  - `QuantityOf` concept introduced
  - `quantity_cast<U, Rep>()` support added

- **0.2.0 July 18, 2019 (C++Now 2019 design)**
  - The design as described on C++Now 2019 talk (<https://youtu.be/wKchCktZPHU>)
  - Added C++20 features supported by gcc-9.1 (`std::remove_cvref_t`, down with typename, `std::type_identity`)
  - Compile-time performance optimizations (`type_list`, `common_ratio`, `ratio`, `conditional_t`)

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