feat: core.h header added

src/core/CMakeLists.txt

@@ -61,6 +61,7 @@ add_library(
     include/mp_units/bits/value_cast.h
 
     include/mp_units/concepts.h
+    include/mp_units/core.h
     include/mp_units/customization_points.h
     include/mp_units/dimension.h
     include/mp_units/quantity.h

src/core/include/mp_units/core.h

@@ -0,0 +1,33 @@
+// 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 <mp_units/concepts.h>
+#include <mp_units/customization_points.h>
+#include <mp_units/dimension.h>
+#include <mp_units/quantity.h>
+#include <mp_units/quantity_point.h>
+#include <mp_units/quantity_spec.h>
+#include <mp_units/reference.h>
+#include <mp_units/system_reference.h>
+#include <mp_units/unit.h>