feat: import std; support added

Resolves #595

test/runtime/atomic_test.cpp

@@ -21,7 +21,11 @@
 // SOFTWARE.
 
 #include <catch2/catch_test_macros.hpp>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <atomic>
+#endif
 #ifdef MP_UNITS_MODULES
 import mp_units;
 #else

test/runtime/distribution_test.cpp

@@ -21,12 +21,16 @@
 // SOFTWARE.
 
 #include <catch2/catch_test_macros.hpp>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <array>
 #include <cstddef>
 #include <cstdint>
 #include <initializer_list>
 #include <random>
 #include <vector>
+#endif
 #ifdef MP_UNITS_MODULES
 import mp_units;
 #else

test/runtime/fixed_string_test.cpp

@@ -24,8 +24,12 @@
 #include <catch2/matchers/catch_matchers_exception.hpp>
 #include <mp-units/compat_macros.h>
 #include <mp-units/ext/format.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <sstream>
 #include <string_view>
+#endif
 #ifdef MP_UNITS_MODULES
 import mp_units;
 #else

test/runtime/fmt_test.cpp

@@ -25,6 +25,9 @@
 #include <catch2/matchers/catch_matchers_exception.hpp>
 #include <mp-units/compat_macros.h>
 #include <mp-units/ext/format.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <cstdint>
 #include <iomanip>
 #include <limits>
@@ -32,6 +35,7 @@
 #include <sstream>
 #include <string>
 #include <string_view>
+#endif
 #ifdef MP_UNITS_MODULES
 import mp_units;
 #else

test/runtime/linear_algebra_test.cpp

@@ -23,8 +23,12 @@
 #include <catch2/catch_test_macros.hpp>
 #include <mp-units/compat_macros.h>
 #include <mp-units/ext/format.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <matrix>
 #include <ostream>
+#endif
 #ifdef MP_UNITS_MODULES
 import mp_units;
 #else

test/runtime/math_test.cpp

@@ -23,7 +23,11 @@
 #include "almost_equals.h"
 #include <catch2/catch_test_macros.hpp>
 #include <catch2/matchers/catch_matchers.hpp>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <limits>
+#endif
 #ifdef MP_UNITS_MODULES
 import mp_units;
 #else

test/runtime/truncation_test.cpp

@@ -25,8 +25,12 @@
 #include <catch2/catch_test_macros.hpp>
 #include <catch2/matchers/catch_matchers.hpp>
 #include <mp-units/ext/format.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <limits>
 #include <numbers>
+#endif
 #ifdef MP_UNITS_MODULES
 import mp_units;
 #else

test/static/angular_test.cpp

@@ -21,7 +21,11 @@
 // SOFTWARE.
 
 #include <mp-units/systems/isq_angle.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <numbers>
+#endif
 
 namespace {
 

test/static/chrono_test.cpp

@@ -25,9 +25,13 @@
 #include <mp-units/framework/quantity_point.h>  // IWYU pragma: keep
 #include <mp-units/systems/isq/si_quantities.h>
 #include <mp-units/systems/si.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <chrono>
 #include <concepts>
 #include <ratio>
+#endif
 
 namespace {
 

test/static/concepts_test.cpp

@@ -23,6 +23,9 @@
 #include <mp-units/systems/isq/space_and_time.h>
 #include <mp-units/systems/natural.h>
 #include <mp-units/systems/si.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <optional>
 #include <type_traits>
 #if MP_UNITS_HOSTED
@@ -30,6 +33,7 @@
 #include <complex>
 #include <string>
 #endif
+#endif
 
 #if MP_UNITS_HOSTED
 template<typename T>

test/static/custom_rep_test_min_expl.cpp

@@ -20,8 +20,12 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <ostream>
 #include <type_traits>
+#endif
 #ifdef MP_UNITS_MODULES
 import mp_units;
 #else

test/static/custom_rep_test_min_impl.cpp

@@ -24,8 +24,12 @@
 #include <mp-units/framework.h>
 #include <mp-units/systems/si/prefixes.h>
 #include <mp-units/systems/si/units.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <concepts>
 #include <type_traits>
+#endif
 
 namespace {
 

test/static/dimension_symbol_test.cpp

@@ -22,7 +22,11 @@
 
 #include <mp-units/framework.h>
 #include <mp-units/systems/isq.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <string_view>
+#endif
 
 namespace {
 

test/static/dimension_test.cpp

@@ -23,7 +23,11 @@
 #include "test_tools.h"
 #include <mp-units/ext/type_traits.h>
 #include <mp-units/framework.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <type_traits>
+#endif
 
 namespace {
 

test/static/fixed_string_test.cpp

@@ -21,8 +21,12 @@
 // SOFTWARE.
 
 #include <mp-units/ext/fixed_string.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <array>
 #include <string_view>
+#endif
 
 using namespace mp_units;
 

test/static/prime_test.cpp

@@ -21,9 +21,13 @@
 // SOFTWARE.
 
 #include <mp-units/ext/prime.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <array>
 #include <cstddef>
 #include <utility>
+#endif
 
 using namespace mp_units::detail;
 

test/static/quantity_point_test.cpp

@@ -26,6 +26,9 @@
 #include <mp-units/systems/isq.h>
 #include <mp-units/systems/si.h>
 #include <mp-units/systems/usc.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <concepts>
 #include <cstdint>
 #include <limits>
@@ -34,6 +37,7 @@
 #if MP_UNITS_HOSTED
 #include <chrono>
 #endif
+#endif
 
 namespace {
 

test/static/quantity_spec_test.cpp

@@ -23,7 +23,11 @@
 #include "test_tools.h"
 #include <mp-units/ext/type_traits.h>
 #include <mp-units/framework.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <type_traits>
+#endif
 
 namespace {
 

test/static/quantity_test.cpp

@@ -27,6 +27,9 @@
 #include <mp-units/systems/isq/mechanics.h>
 #include <mp-units/systems/isq/space_and_time.h>
 #include <mp-units/systems/si.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <concepts>
 #include <cstdint>
 #include <limits>
@@ -35,6 +38,7 @@
 #if MP_UNITS_HOSTED
 #include <chrono>
 #endif
+#endif
 
 template<>
 inline constexpr bool mp_units::is_vector<int> = true;

test/static/reference_test.cpp

@@ -23,8 +23,12 @@
 #include "test_tools.h"
 #include <mp-units/framework.h>
 #include <mp-units/systems/si/prefixes.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <cstdint>
 #include <type_traits>
+#endif
 
 namespace {
 

test/static/si_test.cpp

@@ -21,7 +21,11 @@
 // SOFTWARE.
 
 #include <mp-units/systems/si.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <type_traits>
+#endif
 
 namespace {
 

test/static/test_tools.h

@@ -24,7 +24,11 @@
 
 #include <mp-units/bits/hacks.h>
 #include <mp-units/framework/quantity_spec.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <type_traits>
+#endif
 
 template<auto V, typename T>
 inline constexpr bool is_of_type = std::is_same_v<MP_UNITS_REMOVE_CONST(decltype(V)), T>;

test/static/type_list_test.cpp

@@ -22,7 +22,11 @@
 
 #include <mp-units/bits/type_list.h>
 #include <mp-units/ext/type_traits.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <type_traits>
+#endif
 
 namespace {
 

test/static/unit_symbol_test.cpp

@@ -23,7 +23,11 @@
 #include <mp-units/systems/iau.h>
 #include <mp-units/systems/iec80000.h>
 #include <mp-units/systems/si.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <string_view>
+#endif
 
 namespace {
 

test/static/unit_test.cpp

@@ -24,7 +24,11 @@
 #include <mp-units/ext/type_traits.h>
 #include <mp-units/framework.h>
 #include <mp-units/systems/si/prefixes.h>
+#ifdef MP_UNITS_IMPORT_STD
+import std;
+#else
 #include <type_traits>
+#endif
 
 namespace {