coherent_derived_unit and custom prefixes support added

src/include/units/prefix.h

@@ -0,0 +1,68 @@
+// The MIT License (MIT)
+//
+// Copyright (c) 2018 Mateusz Pusz
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#pragma once
+
+#include <units/unit.h>
+#include <units/format.h>
+
+namespace units {
+
+  // prefix tags
+  struct si_prefix;
+  
+  // SI prefixes
+
+  template<Unit U> using atto = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<1, std::atto::den>>>;
+  template<Unit U> using femto = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<1, std::femto::den>>>;
+  template<Unit U> using pico = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<1, std::pico::den>>>;
+  template<Unit U> using nano = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<1, std::nano::den>>>;
+  template<Unit U> using micro = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<1, std::micro::den>>>;
+  template<Unit U> using milli = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<1, std::milli::den>>>;
+  template<Unit U> using centi = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<1, std::centi::den>>>;
+  template<Unit U> using deca = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<std::deca::num>>>;
+  template<Unit U> using hecto = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<std::hecto::num>>>;
+  template<Unit U> using kilo = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<std::kilo::num>>>;
+  template<Unit U> using mega = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<std::mega::num>>>;
+  template<Unit U> using giga = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<std::giga::num>>>;
+  template<Unit U> using tera = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<std::tera::num>>>;
+  template<Unit U> using peta = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<std::peta::num>>>;
+  template<Unit U> using exa = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<std::exa::num>>>;
+
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<1, std::atto::den>> = "a";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<1, std::femto::den>> = "f";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<1, std::pico::den>> = "p";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<1, std::nano::den>> = "n";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<1, std::micro::den>> = "\u00b5\u0073";  // µ
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<1, std::milli::den>> = "m";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<1, std::centi::den>> = "c";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<1, std::deci::den>> = "d";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<std::deca::num>> = "da";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<std::hecto::num>> = "h";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<std::kilo::num>> = "k";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<std::mega::num>> = "M";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<std::giga::num>> = "G";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<std::tera::num>> = "T";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<std::peta::num>> = "P";
+  template<> inline constexpr std::string_view prefix_symbol<si_prefix, ratio<std::exa::num>> = "E";
+
+}