Added concentration

src/include/units/physical/dimensions.h

@@ -134,6 +134,9 @@ struct dim_absorbed_dose : derived_dimension<Child, U, exp<E, 1>, exp<M, -1>> {}
 template<typename Child, Unit U, DimensionOf<dim_electric_current> I, DimensionOf<dim_length> L>
 struct dim_current_density : derived_dimension<Child, U, exp<I, 1>, exp<L, -2>> {};
 
+template<typename Child, Unit U, DimensionOf<dim_substance> M, DimensionOf<dim_length> L>
+struct dim_concentration : derived_dimension<Child, U, exp<M, 1>, exp<L, -3>> {};
+
 }  // namespace physical
 
 template<typename T>
@@ -223,4 +226,7 @@ concept AbsorbedDose = physical::QuantityOf<T, physical::dim_absorbed_dose>;
 template<typename T>
 concept CurrentDensity = physical::QuantityOf<T, physical::dim_current_density>;
 
+template<typename T>
+concept Concentration = physical::QuantityOf<T, physical::dim_concentration>;
+
 }  // namespace units

src/include/units/physical/si.h

@@ -26,6 +26,7 @@
 #include "si/area.h"
 #include "si/capacitance.h"
 #include "si/catalytic_activity.h"
+#include "si/concentration.h"
 #include "si/conductance.h"
 #include "si/constants.h"
 #include "si/current_density.h"

src/include/units/physical/si/concentration.h

@@ -0,0 +1,47 @@
+// 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/physical/dimensions.h>
+#include <units/physical/si/length.h>
+#include <units/physical/si/substance.h>
+#include <units/quantity.h>
+
+namespace units::si {
+
+struct mol_per_metre_cub : unit<mol_per_metre_cub> {};
+struct dim_concentration : physical::dim_concentration<dim_concentration, mol_per_metre_cub, dim_substance, dim_length> {};
+
+template<Unit U, Scalar Rep = double>
+using concentration = quantity<dim_concentration, U, Rep>;
+
+inline namespace literals {
+
+// mol/m³
+constexpr auto operator"" q_mol_per_m3(unsigned long long l) { return concentration<mol_per_metre_cub, std::int64_t>(l); }
+constexpr auto operator"" q_mol_per_m3(long double l) { return concentration<mol_per_metre_cub, long double>(l); }
+
+}  // namespace literals
+
+}  // namespace units::si
+