CHANGELOG.md

Release Notes

mp-units

2.5.0 WIP { id="2.5.0" }

2.4.0 November 5, 2024 { id="2.4.0" }

• (!) feat: phase_velocity and group_velocity aliases removed from ISQ by ISO
• feat: iec::bit using-declared in iec::unit_symbols
• feat: common unit symbols now use EQUIV{u1, u2, ...} syntax
• feat: scaled_unit symbol printing improved ([] around the entire unit, small magnitude values do not use a power of 10 anymore)
• feat: scaled_unit does not have a priority over derived_unit anymore
• feat: fractional exponents support added to mag_power
• feat: tag types are now required to be empty
• feat: magnitude text now obeys formatting parameters and knows how to print constants
• feat: added support for printing powers of magnitude constants
• feat: SymbolicConstant concept added
• feat: common_unit selection algorithm improved to make rev + rad return rad
• feat: litre text symbol changed from l to L to avoid ambiguity with 1
• feat: alternative litre unit symbol L added to prevent ambiguities with 1
• feat: Unicode unit symbols
• feat: π added as an alias for pi
• feat: expr_pow extended to remove redundancy in callers
• feat: DerivedDimensionExpr, DerivedQuantitySpecExpr and DerivedUnitExpr removed
• feat: MagnitudeSpecExpr and PowerVBase removed and some functions renamed to limit possible ambiguity in overload resolution
• feat: std::is_object constraint applied to value_type_t
• feat: quantity_values are now defined on top of std::chrono::duration_values
• feat: from now on truncation is not allowed in compound assignment
• feat(example): currency example now uses chrono::time_point and has better interfaces
• feat(example): treat_as_floating_point specializations for examples' types removed
• (!) refactor: all iec quantity specifications are now deprecated and moved to isq
• (!) refactor: mag_constant now takes a symbol and a value and the class deriving from it must be final
• (!) refactor: op==(U1, U2) now checks for the same type (old behavior available as equivalent(U1, U2)) + convertible now verifies associated quantity_spec as well
• (!) refactor: ascii -> portable, unicode -> utf8, 'A' -> 'P'
• (!) refactor: char_traits removed from fixed_string
• (!) refactor: convertibility traits and concepts refactored to use bool flags instead of wrappers
• (!) refactor: tag types should not expose their members
• refactor: convertible(U1, U2) implementation simplified
• refactor: abs moved to constexpr_math.h
• refactor: unit_symbol_impl simplified
• refactor: unit_symbol_formatting moved to a dedicated header file
• refactor: shorten_T removed
• refactor: magnitude interface cleanup
• refactor: derived_from_the_same_base_dimension no longer needed
• refactor: one_of usage removed from the fixed_string deduction guides
• refactor: quantity.h is not needed in constants.h (unit.h is enough)
• refactor: SameDimension concept is not needed and can be inlined in DimensionOf
• refactor: framework Unicode symbols are now spelled using their codes
• refactor: QuantitySpecWithNoSpecifiers removed and kind_of definition simplified
• refactor: treat_as_floating_point simplified and extended to use std::chrono::treat_as_floating_point_v
• refactor: wrapped_type_t reuses std::indirectly_readable_traits
• refactor: expr_fractions takes direct OneType type now instead of a trait
• refactor: Unicode symbols description reworked based on the latest SG16 recommendations
• refactor: Mutable concept applied to quantity and quantity_point
• refactor: explicit cleanup for deduction guides of quantity and quantity_point
• refactor: point_origin_interface::op- cleanup
• refactor: QuantityLikeImpl refactored to conform to API Reference by @JohelEGP
• refactor: get_complexity refactored to be 0-based and not account for a number of arguments in a list
• refactor: get_complexity refactored to returned maximum complexity of an element (instead of the sum of elements)
• refactor(test): derived_quantity refactored to child_quantity
• fix: missing are_ingredients_convertible overloads added
• fix: constraints for magnitude added for scaled_unit and fixed common_unit instantiating it incorrectly
• fix: according to ISO 80000-16 % should always be prefixed with space
• fix: extraneous space in unit symbol having only denominators removed
• fix: explicit cast added to less for magnitudes to fix clang-arm64 conversion error
• fix: common_unit handling fixed for some corner cases
• fix: math functions constraints fixed
• fix: operator*(M, U u) fixed for U being scaled_unit
• fix: subsumption of QuantityKindSpec fixed
• fix: ValuePreservingTo fixed to apply std::remove_cvref_t on FromRep
• fix: compound assignment operations on quantities now behave the same as on the underlying representation types
• fix: QuantityConvertibleTo used in quantity_point compound assignment
• fix: convertible_kinds implementation fixed
• fix(tests): freestanding build fixed
• test: unit tests for the inverse of mag_constant added
• test: Unicode symbols used in unit tests
• test: more std::chrono tests added
• test: commutativity tests added to ISQ
• test: one kind_of test added to reference tests
• test: pow<0> and pow<1> tests added for dimensions
• test: more get_common_quantity_spec tests added
• build: setting of some test_package CMake options enabled only for a cxx_modules build
• ci: sudo apt update added for documentation.yml in hope that it will resolve missing system packages issue
• ci: MSVC added to the CI
• ci: the latest not-released docs will use "HEAD" as a version from now on
• ci: documentation action should run on a new tag as well
• ci: documentation action limited only to commits that change documentation files
• ci: non-documentation actions should not run on tags
• docs: missing systems added to the "Project Structure" chapter
• docs: graphs of ISQ kind hierarchies improved
• docs: category of the ISO meeting reports changed to "WG21 Updates"
• docs: blog comments support added
• docs: Part 1-5 articles of the ISQ series added
• docs: "Symbols of scaled units" chapter added + minor updates to scaled and common units chapters
• docs: conan profile updated to present gcc-14 instead of gcc-12 which is no longer supported
• docs: "Why derived units order is not preserved from the multiplication?" chapter added to FAQ
• docs: "Many shades of the same unit" extended with a note about the derived units order
• docs: API Reference now presents index.html instead of full.hml

2.3.0 September 27, 2024 { id="2.3.0" }

• (!) feat: delta and absolute construction helpers
• (!) feat: Conan and CMake options changed as requested at ConanCenter code review
• (!) feat: unit_can_be_prefixed removed - from now on all named units can be prefixed
• feat: formatting functions for units and dimensions marked as constexpr to enable compile-time text formatting
• feat: qp1.quantity_from(qp2) added
• feat: non-member swap added for fixed_string
• feat: simplified inplace_vector added
• feat: text output for angular units improved (space before symbol removed)
• feat: representation type template parameter added to value conversion functions
• feat: all tags in the expression templates are now ordered by the type names
• feat: convertibility of a quantity with a unit one with the raw value added
• feat: import std; support added
• feat: compute values for rational magnitude powers (thanks @chiphogg)
• feat: value_cast<Representation, Unit>() complementary conversion function added
• feat: hw_voltage example added
• feat: MP_UNITS_IMPORT_STD and MP_UNITS_MODULES handled properly in test_package.cpp
• feat: complex quantity character added
• feat: iec::var unit added
• feat: type_list_unique added
• feat: for_each on std::tuple added
• feat: common_unit support added
• (!) refactor: quantity_point_like_traits now use numerical value instead of the quantity
• (!) refactor: iec80000 system renamed to iec
• (!) refactor: mag_pi is now mag<pi>
• (!) refactor: common_XXX() functions renamed to get_common_XXX()
• refactor: error messages-related improvements
• refactor: [[nodiscard]] and consteval set for some magnitude-related functions
• refactor: degree Celsius and Fahrenheit symbols text now use Unicode codepoints
• refactor: dimension_symbol and units_symbol refactored to use inplace_vector
• refactor: unit_symbol and dimension_symbol refactored for readability and consteval
• refactor: binary operators of quantity and quantity_point are now hidden friends
• refactor: tag types-related operators are now hidden friends as well
• refactor: ValuePreservingTo concept added
• refactor: perfect forwarding interfaces improved
• refactor: Representation concepts now requires WeaklyRegular instead of std::regular
• refactor: quantity_point default-constructibility removed from the quantity_from constraints
• refactor: has_common_type_v simplified
• refactor: is_power_of_quantity_spec and is_power_of_dim variable templates converted to concepts
• refactor: unnecessary custom versions of is_specialization_of removed
• refactor: is_derived_from_specialization_of_v added and applied to remove custom traits
• fix: signatures of capacity functions of fixed_string fixed
• fix: MP_UNITS_API_NO_CRTP handling fixed
• fix: MP_UNITS_HOSTED branch added to core.h
• fix: mkdocs dependencies fixed in the gitpod dockerfile
• fix: MP_UNITS_API_CONTRACTS should have a priority over headers availability
• fix: si.h and angular.h now properly include hacks.h to define MP_UNITS_HOSTED before its usage
• fix: quantity scaling between different prefixes improved
• fix: conversion operator to std::chrono types fixed
• fix: std::format does not always use Char* as iterators
• fix: complex_power & co fixed
• fix: __cpp_deleted_function workaround for clang-19 added
• test: conversion to chrono unit tests added
• test: unit tests for creating a quantity from a volatile variable
• test: increase tolerance for certain math tests to two epsilon by @burnpanck
• test: std::complex-based quantities tests added
• build: conanfile bumped to use catch2/3.7.0
• build: conanfile bumped to use fmt/11.0.1
• build: minimum required CMake version bumped to 3.25
• build: duplicated cmake_minimum_required commands removed
• build: minimum conan version set to 2.0.15
• build: MSVC compilation enabled for the library part by @czjhoppe
• build: Dockerfile updated for gitpod
• build: generate() in test_package now correctly propagates project's options
• build: target_include_directories is not needed anymore
• build: target_compile_features now uses CMAKE_CXX_STANDARD
• build: package_type is dynamically set in conanfile.py depending if we build modules or not
• build(conan): packaging improved
• ci: added test for upstream clang on macos-14, as an example for an arm64 platform by @burnpanck
• style: pre-commit updated to clang-format-18.1.8
• docs: "Strong Angular System" chapter added
• docs: docs updated to use new spelling for Conan options
• docs: "Interface Introduction" chapter updated
• docs: St. Louis 2024 report added
• docs: "Radians and degrees support" added
• docs: Rework of "Getting Started" section
• docs: "API Reference" support added (thanks @JohelEGP)
• docs: "Generating API reference" chapter added
• docs: minor formatting and spelling improvements to the "CONTRIBUTING.md"
• docs: "Unit symbols" chapter added
• docs: examples line numbers fixed
• docs: "Text Formatting" tag removed from avg_speed example
• docs: line breaks in mermaid graphs fixed
• docs: 2.3.0 release added

2.2.1 July 3, 2024 { id="2.2.1" }

• (!) feat: Conan and CMake options refactored

2.2.0 June 14, 2024 { id="2.2.0" }

• (!) feat: C++ modules support added by @JohelEGP
• (!) feat: New formatting specification implemented
• (!) feat: has_unit_symbol support removed
• (!) feat: ABI concerns resolved with introduction of u8 strings for symbols
• (!) feat: API-related Conan, CMake, and preprocessor options redesigned
• (!) feat: core.h removed
• (!) feat: from now on units, dimensions, quantity specifications, and point origins have to be marked as final
• feat: implicit point origins support added
• feat: unit default point origin support added
• feat: fma, isfinite, isinf, and isnan math function added by @NAThompson
• feat: fma for quantity points added
• feat: quantity_point support added for quantity_cast and value_cast
• feat: value_cast<Unit, Representation> added
• feat: value_cast<Quantity>(q), value_cast<Quantity>(qp) and value_cast<QuantityPoint>(qp) added by @burnpanck
• feat: interconvertible(QuantitySpec, QuantitySpec) added
• feat: qp.quantity_from_zero() added
• feat: value_type type trait added
• feat: do not print space between a number and percent or per_mille
• feat: ppm parts per million added by @nebkat
• feat: atan2 2-argument arctangent added by @nebkat
• feat: fmod floating-point division remainder added by @nebkat
• feat: remainder IEEE division remainder added by @nebkat
• feat: std::format support added
• feat: unit text output support added
• feat: formatting error messages improved
• feat: improve types readability by eliminating extraneous () in references, prefixes, and kind_of
• feat: dimension and unit text output added
• feat: some light and radiation ISQ quantities added
• feat: allow configuring GSL library use
• feat: freestanding support added
• (!) refactor: zero_Fahrenheit renamed to zeroth_degree_Fahrenheit
• (!) refactor: SI-related trigonometric functions moved to the si subnamespace
• (!) refactor: math.h header file broke up to smaller pieces
• (!) refactor: fixed_string interface refactored
• (!) refactor: ReferenceOf does not take a dimension anymore
• (!) refactor: 'o' replaced with '1' as a modifier for unit_symbol_solidus::one_denominator
• (!) refactor: get_kind() now returns kind_of
• (!) refactor: FMT macros moved to compat_macros.h
• (!) refactor: fixed_string refactored to reflect the latest changes to P3094R2
• (!) refactor: basic_symbol_text renamed to symbol_text
• (!) refactor: ratio hidden as an implementation detail behind mag_ratio
• (!) refactor: framework.h introduced
• (!) refactor: type list tools made an implementation detail of the library
• (!) refactor: header files with the entire system definitions moved up in the directory tree
• (!) refactor: absolute_point_origin does not use CRTP anymore
• refactor: system's units do not inherit from one another anymore
• refactor: all units made final
• refactor: math functions constraints refactored
• refactor: si_quantities.h added to improve compile-times
• refactor: validate_ascii_string refactored to is_basic_literal_character_set
• refactor: underlying_type split to wrapped_type and value_type and used in code
• refactor: code refactored to comply with clang-tidy
• refactor: remove dependency on <ranges> header and switch to use an iterator-based copy algorithm
• refactor: terminate replaced with abort and a header file added
• refactor: most std::remove_const_t removed and some replaced with the GCC-specific workaround
• refactor: not needed remove_reference_t and remove_cvref_t removed
• refactor: binary operators of quantity and quantity_point are now hidden friends
• fix: QuantityLike conversions required Q::rep instead of using one provided by quantity_like_traits
• fix: QuantitySpec[Unit] replaced with make_reference in value_cast
• fix: ice_point is now defined with the integral offset from absolute_zero
• fix: performance regression in sudo_cast fixed
• fix: explicit object parameter support fixed
• fix: missing version header file added to hacks.h
• fix: quantity_cast to accept lvalue references (thanks @burnpanck)
• fix: value_cast with lvalue references to quantity_point (thanks @burnpanck)
• docs: project blog and first posts added
• docs: project documentation layout refactored
• docs: "Interoperability with Other Libraries" chapter added
• docs: "Framework Basics" chapters updated and cleaned up
• docs: smoot unit example added to the main page
• docs: "Code Example" chapter renamed to "Look and Feel" and reordered in TOC to be after "Quick Start"
• docs: "Quick Start" chapter reworked to be simpler and include quantity points
• docs: "Quantity points" chapter extended
• docs: "The Affine Space" chapter updated to reflect the recent design changes
• docs: "Working with Legacy interfaces" chapter added
• docs: "Text Output" chapter updated
• docs: mkdocs social plugin enabled
• docs: project logo and custom color scheme added
• docs: minimum compiler requirements updated
• docs: unit symbols admonition extended in the "Quick Start" chapter
• docs: Cairo dependency described in the MkDocs section
• docs: "hello units" example updated with dimensions output
• docs: "Text Output" chapter updated with the recent formatting changes
• docs: formatting grammar language changed to EBNF
• docs: "Project structure" chapter expanded
• docs: CITATION.cff updated
• (!) build: Conan and CMake options refactored
• (!) build: MP_UNITS_AS_SYSTEM_HEADERS renamed to MP_UNITS_BUILD_AS_SYSTEM_HEADERS
• (!) build: MP_UNITS_BUILD_LA and MP_UNITS_IWYU CMake options now have _DEV_ in the name
• build: gsl-lite updated to 0.41.0
• build: catch2 updated to 3.5.1
• build: fmt updated to 10.2.1
• build: gitpod environment updated
• build: check_cxx_feature_supported added
• build: IWYU path handling fixed
• build: IWYU enabled on GCC
• build: CMAKE_EXPORT_COMPILE_COMMANDS flag enabled for the developer's build
• build(conan): generate() now set cache_variables
• build(conan): can_run check added before running tests
• ci: Conan and CMake CI now use different cache names
• ci: gcc-14 added
• ci: clang-tidy CI added

2.1.1 May 16, 2024 { id="2.1.1" }

• fix: unit tests compilation on gcc-14 fixed
• fix: explicit this parameter support fixed

2.1.0 December 9, 2023 { id="2.1.0" }

• (!) feat: inverse() support added for dimensions, quantity_spec, units, and references (1 / s will now create quantity and not a Unit)
• (!) feat: quantity_point does not provide zero() anymore
• (!) feat: quantity_spec and its kind should not compare equal
• (!) feat: mutating interface removed from fixed_string
• (!) feat: common_type with a raw value is not needed anymore as for a long time now raw values are not convertible to the dimensionless quantities
• (!) feat: symbol_text definition simplified
• (!) feat: users are now allowed to inherit their own types from absolute point origins
• (!) feat: interoperability with other libraries redesigned
• feat: basic_fixed_string(const CharT*, std::integral_constant<std::size_t, N>) constructor added
• feat: isq::activity added and becquerel definition updated to benefit from it
• feat: gray and sievert now have correct associated quantity kinds
• feat: UnitCompatibleWith concept added and applied to in(U) and force_in(U) functions
• feat: quantities can now be multiplied and divided by units (no parenthesis needed anymore)
• feat: Magnitude / Unit operator added
• feat: equality for dimensions now will allow derived classes as well (but not from derived_dimension)
• feat: zero_Fahrenheit point origin added
• feat: equivalent point origins handling improved
• feat(example): unit symbols added to the currency example
• (!) refactor: unit_symbol<fmt>(U) signature refactored and the resulting text can now also be used at runtime
• (!) refactor: make_xxx factory functions replaced with two-parameter constructors
• (!) refactor: unit_symbol changed to consteval
• refactor: in(U) and force_in(U) now return auto to provide better diagnostics on clang
• refactor: quantity operators constraints refactored
• refactor: more type members added to fixed_string definition
• refactor: unit_symbol_formatting enums now use std::int8_t as a representation type
• fix: symbols of named dimensionless units with the ratio = 1 were not printed
• fix: iterator is now properly updated for all cases in unit_symbol
• fix: Fahrenheit conversion ratio was inverted
• fix: CommonlyInvocableQuantities was overconstrained for the current library design
• fix: are_ingredients_convertible now mandates explicit conversion for To dimensionless quantities
• fix: quantity_point::point_for(PO) constraints fixed
• fix(example): latitude and longitude fixed to include 0 for N and E respectively
• ci: clang-17 enabled
• ci: apple-clang-15 enabled
• ci: Added C++23 builds to the CI matrix
• docs: "Getting Started" chapters updated
• docs: "Basic Concepts" and "Interface Introduction" chapters updated
• docs: "Design Overview" chapter added and "Concepts" chapter reworked
• docs: "Output stream formatting" chapter updated
• docs: "Default formatting" chapter updated
• docs: "Derived unit symbols generation" chapter added
• docs: outdated affine space chapter updated
• docs: CameCase concept identifiers FAQ added
• docs: gravitational_potential_energy equation fixed on a graph
• docs: YouTube video link updated to the C++ on Sea 2023
• docs: ISO papers reference added to docs and README
• docs: a representation type in a dimensionless quantity FAQ fixed
• docs: titles added to some important admonitions
• docs: "Terms and Definitions" slightly updated
• docs: "canonical unit" added to glossary and its documentation in code was updated
• docs: Design overview graph updated

2.0.0 September 24, 2023 { id="2.0.0" }

• units namespace renamed to mp_units (#317)
• header files in the <mp-units/...> rather then in <units/...> (#317)
• the downcasting facility is removed (#383, #211, #32)
• unified and simplified quantity creation (#274)
• determining the best way to create a quantity (#413)
• V2 quantity_point (#414)
• introduction of quantity_spec to store not only dimension but also additional information about quantities (#405)
• quantity now takes reference object, which aggregates quantity_spec and a unit and a representation type
• units, prefixes, dimensions, quantity specifications, and references are passed as NTTPs to templates and provide arithmetic operations and comparison
• expression templates consistently used in all derived types to increase the readability (#351, #166)
• derived dimensions are now factors of only base dimensions (#281)
• convertibility of derived quantities (#427)
• dimensions, quantity specifications, units, and references are now composable, significantly reducing the number of definitions and resulting types
• heavily simplified unit systems definitions (no need to define unnamed derived units, systems-specific dimensions, aliases for quantities, concepts, UDLs, ... anymore)
• improved definition of all systems
• support for ISO 80000 Part 3-6 quantities
• faster than lightspeed constants (#169)
• extensions to quantity formatting with fmt
• quantity_kind removed
• improved casting of unit with .in(Unit), .force_in(Unit) for quantity and quantity_spec
• numerical value accessor safety improved with .numerical_value_in(Unit) and .force_numerical_value_in(Unit)
• quantity can no longer be constructed with a raw value (#434)
• Implicit construction of quantities from a value (#410)
• quantity_point can no longer be constructed with just a quantity and an explicit PointOrigin is always needed
• ceil and floor are dangerous (#432)
• quecto, ronto, ronna, quetta new SI prefixes support
• comparison against zero added (#487)
• documentation rewritten from scratch
• many smaller changes not possible to address with the previous design (#205, #210, #134)

0.8.0 June 14, 2023 { id="0.8.0" }

• (!) 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)
• feat: floor(), ceil(), and round() support added (thanks @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)
• 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)
• docs: Project documentation updated
• docs: CITATION.cff file added
• docs: CONTRIBUTING.md updated

0.7.0 May 11, 2021 { id="0.7.0" }

• (!) 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)
• feat: quantity references support added (thanks @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)
• feat: SI prefixes for isq::iec80000 support added (thanks @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
• (!) build: Linear Algebra is now hosted on its Artifactory
• (!) 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 { id="0.6.0" }

• feat: quantity_point support added (thanks @johelegp)
• feat: Added angle as SI base dimension (thanks @kwikius)
• feat: si::angular_velocity support added (thanks @mikeford3)
• feat: FPS system added (thanks @mikeford3)
• feat: Added support for mathematical function exp(quantity)
• feat: Localization support for text output added (thanks @rbrugo)
• feat: Added STL random number distribution wrappers (thanks @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)
• refactor: [[nodiscard]] added to many functions
• fix: si::day unit symbol fixed to d (thanks @komputerwiz)
• fix: si::mole unit symbol fixed to mol (thanks @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 { id="0.5.0" }

• 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!)
• SI fundamental constants added
• q_ prefix applied to all the UDLs (thanks @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)
• Representation values formatting extended (thanks @rbrugo)
• Output streams formatting support added
• Linear algebra from std::experimental::math support added
• Named SI units and their dimensions added (thanks @rbrugo
• libfmt updated to 6.2.0
• Added absolute functions and epsilon to math.h (thanks @mikeford3)
• Added a lot of prefixes to named units and introduced alias_unit (thanks @yasamoka)
• Linking with Conan targets only when they exists (#98)
• All physical dimensions and units put into physical namespace
• CMake improvements
• Velocity renamed to speed

Many thanks to GitHub users @oschonrock, @kwikius, and @i-ky for their support in drafting a new library design.

0.4.0 Nov 17, 2019 { id="0.4.0" }

• 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 { id="0.3.1" }

• cmcstl2 dependency changed to range-v3 0.9.1

0.3.0 Sep 16, 2019 { id="0.3.0" }

• 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 { id="0.2.0" }

• 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 { id="0.1.0" }

• Initial library release
• Begin semantic versioning
• The last version to work with gcc-8