do not print permill as milli_scale "m"

Author: gitsbi

common.hpp

@@ -445,6 +445,7 @@ UNLIB_DEFINE_QUANTITY_LITERAL_TRAITS_SCALED (mega ,     ampere_hour     ,   "MAh
 UNLIB_DEFINE_QUANTITY_LITERAL_TRAITS_SCALED (giga ,     ampere_hour     ,   "GAh")
 
 UNLIB_DEFINE_QUANTITY_LITERAL_TRAITS_NOSCALE(       percent             ,    "%" )
+UNLIB_DEFINE_QUANTITY_LITERAL_TRAITS_NOSCALE(       permill             ,    "" ) //"‰"
 
 UNLIB_DEFINE_QUANTITY_LITERAL_TRAITS_NOSCALE(       bar                 ,   "bar")
 

test/test_common.cpp

@@ -10,6 +10,8 @@
 
 namespace {
 
+using unlib::literals::get_quantity_string;
+
 template<typename D, typename F, typename S1, typename S2, typename T>
 bool is_near_equal(const unlib::quantity<D,S1,F,T> lhs, const unlib::quantity<D,S2,F,T> rhs) {
 	using std::max;
@@ -58,8 +60,6 @@ TEST_CASE("common quantities") {
 		}
 	}
 
-	using unlib::literals::get_quantity_string;
-
 	SUBCASE("time") {
 		const         unlib::second<VT>  s{ 1}; CHECK(get_quantity_string( s) ==  "s"); REQUIRE(s.get() ==  1);
 
@@ -756,6 +756,11 @@ TEST_CASE("common quantities") {
 
 		CHECK(std::is_same<unlib::percent<VT>::tag_type, unlib::no_tag>::value);
 
+		CHECK(get_quantity_string(unlib::scalar  <VT,unlib::no_tag>{}) == "");
+		CHECK(get_quantity_string(unlib::fraction<VT              >{}) == "");
+		CHECK(get_quantity_string(unlib::percent <VT              >{}) == "%");
+		CHECK(get_quantity_string(unlib::permill <VT              >{}) == "");
+
 		using namespace unlib::literals;
 
 		const auto power = 1000._kW;