Add reserve_space_for type to allow constructing a vector-like container with a specific capacity.

Author: davidstone

CMakeLists.txt

@@ -345,6 +345,7 @@ target_sources(containers PUBLIC
 		source/containers/reference_wrapper.cpp
 		source/containers/repeat_n.cpp
 		source/containers/reservable.cpp
+		source/containers/reserve_space_for.cpp
 		source/containers/resizable_container.cpp
 		source/containers/resize.cpp
 		source/containers/sentinel_t.cpp

source/containers/containers.cpp

@@ -94,6 +94,7 @@ export import containers.range_view;
 export import containers.reallocation_size;
 export import containers.reference_wrapper;
 export import containers.repeat_n;
+export import containers.reserve_space_for;
 export import containers.resizable_container;
 export import containers.resize;
 export import containers.small_buffer_optimized_vector;

source/containers/reserve_space_for.cpp

@@ -0,0 +1,15 @@
+// Copyright David Stone 2023.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+export module containers.reserve_space_for;
+
+namespace containers {
+
+export template<typename Capacity>
+struct reserve_space_for {
+	Capacity value;
+};
+
+} // namespace containers