Merge branch 'master' into feature/more-value-casts

CHANGELOG.md

@@ -5,11 +5,12 @@
 ### 2.2.0 <small>WIP</small> { id="2.2.0" }
 
 - (!) feat: C++ modules support added by [@JohelEGP](https://github.com/JohelEGP)
-- (!) feat: formatting grammar improved and units formatting support added
+- (!) 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: :boom: `core.h` removed
+- (!) 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](https://github.com/NAThompson)
@@ -29,10 +30,10 @@
 - 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 text output added
+- feat: dimension and unit text output added
 - feat: some light and radiation ISQ quantities added
-- feat: New formatting specification implemented
 - 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
@@ -47,13 +48,18 @@
 - (!) 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
 - 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`
@@ -82,6 +88,7 @@
 - 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
@@ -97,6 +104,7 @@
 - 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 <small>May 16, 2024</small> { id="2.1.1" }
 

conanfile.py

@@ -207,12 +207,13 @@ def set_version(self):
         self.version = version.strip()
 
     def requirements(self):
-        if self.options.contracts == "gsl-lite":
-            self.requires("gsl-lite/0.41.0")
-        elif self.options.contracts == "ms-gsl":
-            self.requires("ms-gsl/4.0.0")
-        if self._use_fmtlib and not self.options.freestanding:
-            self.requires("fmt/10.2.1")
+        if not self.options.freestanding:
+            if self.options.contracts == "gsl-lite":
+                self.requires("gsl-lite/0.41.0")
+            elif self.options.contracts == "ms-gsl":
+                self.requires("ms-gsl/4.0.0")
+            if self._use_fmtlib:
+                self.requires("fmt/10.2.1")
 
     def build_requirements(self):
         if self._build_all:
@@ -248,17 +249,19 @@ def generate(self):
             tc.cache_variables["MP_UNITS_BUILD_CXX_MODULES"] = str(
                 self.options.cxx_modules
             ).upper()
-        tc.cache_variables["MP_UNITS_API_STD_FORMAT"] = str(
-            self.options.std_format
-        ).upper()
+        if self.options.freestanding:
+            tc.cache_variables["MP_UNITS_API_FREESTANDING"] = True
+        else:
+            tc.cache_variables["MP_UNITS_API_STD_FORMAT"] = str(
+                self.options.std_format
+            ).upper()
         tc.cache_variables["MP_UNITS_API_STRING_VIEW_RET"] = str(
             self.options.string_view_ret
         ).upper()
         tc.cache_variables["MP_UNITS_API_NO_CRTP"] = str(self.options.no_crtp).upper()
         tc.cache_variables["MP_UNITS_API_CONTRACTS"] = str(
             self.options.contracts
         ).upper()
-        tc.cache_variables["MP_UNITS_API_FREESTANDING"] = self.options.freestanding
         tc.generate()
         deps = CMakeDeps(self)
         deps.generate()
@@ -285,13 +288,39 @@ def package(self):
 
     def package_info(self):
         compiler = self.settings.compiler
-        self.cpp_info.components["core"]
-        if self.options.contracts == "gsl-lite":
-            self.cpp_info.components["core"].requires = ["gsl-lite::gsl-lite"]
+
+        # handle contracts
+        if self.options.contracts == "none":
+            self.cpp_info.components["core"].defines.append("MP_UNITS_API_CONTRACTS=0")
+        elif self.options.contracts == "gsl-lite":
+            self.cpp_info.components["core"].requires.append("gsl-lite::gsl-lite")
+            self.cpp_info.components["core"].defines.append("MP_UNITS_API_CONTRACTS=2")
         elif self.options.contracts == "ms-gsl":
-            self.cpp_info.components["core"].requires = ["ms-gsl::ms-gsl"]
-        if self._use_fmtlib and not self.options.freestanding:
+            self.cpp_info.components["core"].requires.append("ms-gsl::ms-gsl")
+            self.cpp_info.components["core"].defines.append("MP_UNITS_API_CONTRACTS=3")
+
+        # handle API options
+        if self.options.string_view_ret != "auto":
+            self.cpp_info.components["core"].defines.append(
+                "MP_UNITS_API_STRING_VIEW_RET="
+                + str(int(self.options.string_view_ret == True))
+            )
+        if self.options.no_crtp != "auto":
+            self.cpp_info.components["core"].defines.append(
+                "MP_UNITS_API_NO_CRTP=" + str(int(self.options.no_crtp == True))
+            )
+        if self.options.std_format != "auto":
+            self.cpp_info.components["core"].defines.append(
+                "MP_UNITS_API_STD_FORMAT=" + str(int(self.options.std_format == True))
+            )
+        if self._use_fmtlib:
             self.cpp_info.components["core"].requires.append("fmt::fmt")
+
+        # handle hosted configuration
+        if not self.options.freestanding:
+            self.cpp_info.components["core"].defines.append("MP_UNITS_HOSTED=1")
+
         if compiler == "msvc":
             self.cpp_info.components["core"].cxxflags = ["/utf-8"]
+
         self.cpp_info.components["systems"].requires = ["core"]

docs/blog/posts/2.2.0-released.md

@@ -172,7 +172,7 @@ Additionally, some CMake options were renamed to better express the impact on ou
 Before this release, the library always depended on [gsl-lite](https://github.com/gsl-lite/gsl-lite)
 to perform runtime contract and asserts checking. In this release we introduced new options
 to control if contract checking should be based on [gsl-lite](https://github.com/gsl-lite/gsl-lite),
-[ms-gsl](https://github.com/microsoft/GSL), or maybe completely disabled.
+[ms-gsl](https://github.com/microsoft/GSL), or may be completely disabled.
 
 
 ## Freestanding support
@@ -205,7 +205,7 @@ origins. For example:
 === "Before"
 
     ```cpp
-    constexpr struct zero : absolute_point_origin<zero, currency> {} zero;
+    constexpr struct zero final : absolute_point_origin<currency> {} zero;
 
     quantity_point price_usd = zero + 100 * USD;
     ```
@@ -260,6 +260,16 @@ named with its corresponding unit and with the `si::zeroth_degree_Celsius`
 
 ## Changes to units definitions
 
+There were several known issues when units were deriving from each other
+(e.g., [#512](https://github.com/mpusz/mp-units/issues/512) and
+[#537](https://github.com/mpusz/mp-units/issues/537)). We could either highly complicate the
+framework to allow these which could result in much longer compilation times or disallow inheriting
+from units at all. We chose the second option.
+
+With this release all of of the units must be marked as `final`. To enforce this we have changed
+the definition of the `Unit<T>` concept, which now requires type `T` to be `final`
+(:boom: **breaking change** :boom:).
+
 [WG21 Study Group 16 (Unicode) raised concerns](https://github.com/sg16-unicode/sg16-meetings#january-24th-2024)
 about potential ABI issues when different translation units are compiled with different ordinary
 literal encodings. Those issues were resolved with a change to units definitions
@@ -272,7 +282,7 @@ is why it was renamed to `symbol_text` (:boom: **breaking change** :boom:).
 === "Now"
 
     ```cpp
-    inline constexpr struct ohm : named_unit<symbol_text{u8"Ω", "ohm"}, volt / ampere> {} ohm;
+    inline constexpr struct ohm final : named_unit<symbol_text{u8"Ω", "ohm"}, volt / ampere> {} ohm;
     ```
 
 === "Before"
@@ -286,9 +296,48 @@ is why it was renamed to `symbol_text` (:boom: **breaking change** :boom:).
     On C++20-compliant compilers it should be enough to type the following in the unit's definition:
 
     ```cpp
-    inline constexpr struct ohm : named_unit<{u8"Ω", "ohm"}, volt / ampere> {} ohm;
+    inline constexpr struct ohm final : named_unit<{u8"Ω", "ohm"}, volt / ampere> {} ohm;
+    ```
+
+
+## Changes to dimension, quantity specification, and point origins definitions
+
+Similarly to units, now also all dimensions, quantity specifications, and point origins have to be
+marked `final` (:boom: **breaking change** :boom:).
+
+=== "Now"
+
+    ```cpp
+    inline constexpr struct dim_length final : base_dimension<"L"> {} dim_length;
+    inline constexpr struct length final : quantity_spec<dim_length> {} length;
+
+    inline constexpr struct absolute_zero final : absolute_point_origin<isq::thermodynamic_temperature> {} absolute_zero;
+    inline constexpr auto zeroth_kelvin  = absolute_zero;
+    inline constexpr struct kelvin final : named_unit<"K", kind_of<isq::thermodynamic_temperature>, zeroth_kelvin> {} kelvin;
+
+    inline constexpr struct ice_point final : relative_point_origin<quantity_point{273'150 * milli<kelvin>}> {} ice_point;
+    inline constexpr auto zeroth_degree_Celsius = ice_point;
+    inline constexpr struct degree_Celsius final : named_unit<symbol_text{u8"°C", "`C"}, kelvin, zeroth_degree_Celsius> {} degree_Celsius;
     ```
 
+=== "Before"
+
+    ```cpp
+    inline constexpr struct dim_length : base_dimension<"L"> {} dim_length;
+    inline constexpr struct length : quantity_spec<dim_length> {} length;
+
+    inline constexpr struct absolute_zero : absolute_point_origin<absolute_zero, isq::thermodynamic_temperature> {} absolute_zero;
+    inline constexpr struct zeroth_kelvin : decltype(absolute_zero) {} zeroth_kelvin;
+    inline constexpr struct kelvin : named_unit<"K", kind_of<isq::thermodynamic_temperature>, zeroth_kelvin> {} kelvin;
+
+    inline constexpr struct ice_point : relative_point_origin<quantity_point{273'150 * milli<kelvin>}> {} ice_point;
+    inline constexpr struct zeroth_degree_Celsius : decltype(ice_point) {} zeroth_degree_Celsius;
+    inline constexpr struct degree_Celsius : named_unit<symbol_text{u8"°C", "`C"}, kelvin, zeroth_degree_Celsius> {} degree_Celsius;
+    ```
+
+Please also note, that the `absolute_point_origin` does not use CRTP idiom anymore (:boom: **breaking change** :boom:).
+
+
 ## Improved text output
 
 With this release, we can print not only whole quantities but also just their units or dimensions.
@@ -461,8 +510,8 @@ conversion factor. Here is a comparison of the code with previous and current de
 === "Now"
 
     ```cpp
-    inline constexpr struct yard : named_unit<"yd", mag_ratio<9'144, 10'000> * si::metre> {} yard;
-    inline constexpr struct foot : named_unit<"ft", mag_ratio<1, 3> * yard> {} foot;
+    inline constexpr struct yard final : named_unit<"yd", mag_ratio<9'144, 10'000> * si::metre> {} yard;
+    inline constexpr struct foot final : named_unit<"ft", mag_ratio<1, 3> * yard> {} foot;
     ```
 
 === "Before"

docs/getting_started/installation_and_usage.md

@@ -342,7 +342,7 @@ tools.build:compiler_executables={"c": "gcc-12", "cpp": "g++-12"}
 
 [`MP_UNITS_API_STD_FORMAT`](#MP_UNITS_API_STD_FORMAT){ #MP_UNITS_API_STD_FORMAT }
 
-:   [:octicons-tag-24: 2.2.0][use fmtlib support] · :octicons-milestone-24: `AUTO`/`ON`/`OFF` (Default: `AUTO`)
+:   [:octicons-tag-24: 2.2.0][use fmtlib support] · :octicons-milestone-24: `AUTO`/`TRUE`/`FALSE` (Default: `AUTO`)
 
     Enables the usage of [`std::format`](https://en.cppreference.com/w/cpp/utility/format/format)
     and associated facilities for text formatting. If it is not supported, then
@@ -352,7 +352,7 @@ tools.build:compiler_executables={"c": "gcc-12", "cpp": "g++-12"}
 
 [`MP_UNITS_API_STRING_VIEW_RET`](#MP_UNITS_API_STRING_VIEW_RET){ #MP_UNITS_API_STRING_VIEW_RET }
 
-:   [:octicons-tag-24: 2.2.0][cmake returning string_view] · :octicons-milestone-24: `AUTO`/`ON`/`OFF` (Default: `AUTO`)
+:   [:octicons-tag-24: 2.2.0][cmake returning string_view] · :octicons-milestone-24: `AUTO`/`TRUE`/`FALSE` (Default: `AUTO`)
 
     Enables returning `std::string_view` from the
     [`unit_symbol()`](../users_guide/framework_basics/text_output.md#unit_symbol)
@@ -364,7 +364,7 @@ tools.build:compiler_executables={"c": "gcc-12", "cpp": "g++-12"}
 
 [`MP_UNITS_API_NO_CRTP`](#MP_UNITS_API_NO_CRTP){ #MP_UNITS_API_NO_CRTP }
 
-:   [:octicons-tag-24: 2.2.0][cmake no crtp support] · :octicons-milestone-24: `AUTO`/`ON`/`OFF` (Default: `AUTO`)
+:   [:octicons-tag-24: 2.2.0][cmake no crtp support] · :octicons-milestone-24: `AUTO`/`TRUE`/`FALSE` (Default: `AUTO`)
 
     Removes the need for the usage of the CRTP idiom in the
     [`quantity_spec` definitions](../users_guide/framework_basics/systems_of_quantities.md#defining-quantities).

docs/index.md

@@ -33,7 +33,7 @@ The library source code is hosted on [GitHub](https://github.com/mpusz/mp-units)
 
     using namespace mp_units;
 
-    inline constexpr struct smoot : named_unit<"smoot", mag<67> * usc::inch> {} smoot;
+    inline constexpr struct smoot final : named_unit<"smoot", mag<67> * usc::inch> {} smoot;
 
     int main()
     {
@@ -53,7 +53,7 @@ The library source code is hosted on [GitHub](https://github.com/mpusz/mp-units)
 
     using namespace mp_units;
 
-    inline constexpr struct smoot : named_unit<"smoot", mag<67> * usc::inch> {} smoot;
+    inline constexpr struct smoot final : named_unit<"smoot", mag<67> * usc::inch> {} smoot;
 
     int main()
     {
@@ -69,7 +69,7 @@ Output:
 Harvard Bridge length = 364.4 smoot (2034.6 ft, 620.14 m) ± 1 εar
 ```
 
-!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/zsW1f6Tn1)"
+!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/f8f4KnKh8)"
 
 ??? question "What is `smoot`?"
 

docs/users_guide/examples/avg_speed.md

@@ -7,7 +7,7 @@ tags:
 
 # `avg_speed`
 
-!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/EYo7879qd)"
+!!! example "[Try it on Compiler Explorer](https://godbolt.org/z/TnqGa4sdn)"
 
 Let's continue the previous example. This time, our purpose will not be to showcase as many
 library features as possible, but we will scope on different interfaces one can provide