Add capitalize()

Author: martinmoene

README.md

@@ -125,7 +125,8 @@ The following table presents types, values and simplified, short prototypes of t
 |           | size_t **find_last_of**(string_view sv, string_view set)                           | position of last occurrence of character in set, or npos                                          |
 |           | size_t **find_last_not_of**(string_view sv, string_view set)                       | position of last occurrence of character not in set, or npos                                      |
 |           |                                                                               |                                                                                              |
-| **Modifiers**  | char_t **to_lowercase**(char_t chr)                                                | character transformed to lowercase                                                                |
+| **Modifiers**  | char_t **capitalize**(char_t chr)                                                  | string transformed to start with capital                                                          |
+|           | char_t **to_lowercase**(char_t chr)                                                | character transformed to lowercase                                                                |
 |           | char_t **to_uppercase**(char_t chr)                                                | character transformed to uppercase                                                                |
 |           | string **to_lowercase**(string_view sv)                                            | string transformed to lowercase                                                                   |
 |           | string **to_uppercase**(string_view sv)                                            | string transformed to uppercase                                                                   |

include/nonstd/string.hpp

@@ -937,7 +937,7 @@ string_nodiscard std::size_t find_first( std17::basic_string_view<CharT> text, S
 namespace string {
 namespace detail {
 
-    // Transform case (character):
+// Transform case (character):
 
 template< typename CharT >
 string_nodiscard CharT to_lowercase( CharT chr )
@@ -967,8 +967,22 @@ string_nodiscard std::basic_string<CharT> to_case( std::basic_string<CharT> text
 } // namespace detail
 } // namespace string
 
-// to_lowercase()
-// to_uppercase()
+// capitalize():
+
+#define string_MK_CAPITALIZE(CharT)                             \
+    string_nodiscard inline std::basic_string<CharT>            \
+    capitalize( std17::basic_string_view<CharT> text )          \
+    {                                                           \
+        if ( text.empty() )                                     \
+            return {};                                          \
+                                                                \
+        std::basic_string<CharT> result{ to_string( text ) };   \
+        result[0] = to_uppercase( result[0] );                  \
+                                                                \
+        return result;                                          \
+    }
+
+// to_lowercase(), to_uppercase():
 
 // template string_nodiscard std::basic_string<CharT> to_lowercase( std17::basic_string_view<CharT> text ) string_noexcept;
 
@@ -1674,6 +1688,7 @@ string_MK_TO_CASE_CHAR     ( char, lowercase )
 string_MK_TO_CASE_CHAR     ( char, uppercase )
 string_MK_TO_CASE_STRING   ( char, lowercase )
 string_MK_TO_CASE_STRING   ( char, uppercase )
+string_MK_CAPITALIZE       ( char )
 string_MK_JOIN             ( char )
 string_MK_SPLIT_DELIM      ( char )
 string_MK_SPLIT_STRING     ( char )
@@ -1714,6 +1729,7 @@ string_MK_TO_CASE_CHAR     ( wchar_t, lowercase )
 string_MK_TO_CASE_CHAR     ( wchar_t, uppercase )
 string_MK_TO_CASE_STRING   ( wchar_t, lowercase )
 string_MK_TO_CASE_STRING   ( wchar_t, uppercase )
+string_MK_CAPITALIZE       ( wchar_t )
 string_MK_JOIN             ( wchar_t )
 string_MK_SPLIT_DELIM      ( wchar_t )
 string_MK_SPLIT_STRING     ( wchar_t )
@@ -1754,6 +1770,7 @@ string_MK_TO_CASE_CHAR     ( char8_t, lowercase )
 string_MK_TO_CASE_CHAR     ( char8_t, uppercase )
 string_MK_TO_CASE_STRING   ( char8_t, lowercase )
 string_MK_TO_CASE_STRING   ( char8_t, uppercase )
+string_MK_CAPITALIZE       ( char8_t )
 string_MK_JOIN             ( char8_t )
 string_MK_SPLIT_DELIM      ( char8_t )
 string_MK_SPLIT_STRING     ( char8_t )
@@ -1794,6 +1811,7 @@ string_MK_TO_CASE_CHAR     ( char16_t, lowercase )
 string_MK_TO_CASE_CHAR     ( char16_t, uppercase )
 string_MK_TO_CASE_STRING   ( char16_t, lowercase )
 string_MK_TO_CASE_STRING   ( char16_t, uppercase )
+string_MK_CAPITALIZE       ( char16_t )
 string_MK_JOIN             ( char16_t )
 string_MK_SPLIT_DELIM      ( char16_t )
 string_MK_SPLIT_STRING     ( char16_t )
@@ -1834,6 +1852,7 @@ string_MK_TO_CASE_CHAR     ( char32_t, lowercase )
 string_MK_TO_CASE_CHAR     ( char32_t, uppercase )
 string_MK_TO_CASE_STRING   ( char32_t, lowercase )
 string_MK_TO_CASE_STRING   ( char32_t, uppercase )
+string_MK_CAPITALIZE       ( char32_t )
 string_MK_JOIN             ( char32_t )
 string_MK_SPLIT_DELIM      ( char32_t )
 string_MK_SPLIT_STRING     ( char32_t )
@@ -1874,6 +1893,7 @@ string_MK_SPLIT_LEFT_STRING( char32_t )
 #undef string_MK_TO_CASE_CHAR
 #undef string_MK_TO_CASE_STRING
 #undef string_MK_TO_CASE_STRING
+#undef string_MK_CAPITALIZE
 #undef string_MK_JOIN
 #undef string_MK_SPLIT_DELIM
 #undef string_MK_SPLIT_STRING

test/string.t.cpp

@@ -1281,7 +1281,15 @@ CASE( "find_last_not_of: position of character in set in string - string_view-st
 
 // Modifiers:
 
-// to_lowercase(), to_uppercase:
+// capitalize():
+
+CASE( "capitalize: Return string starting with capital - string" )
+{
+    EXPECT( capitalize("hello, world!") == "Hello, world!" );
+    EXPECT( capitalize("Hello, world!") == "Hello, world!" );
+}
+
+// to_lowercase(), to_uppercase():
 
 CASE( "to_lowercase: Return char in lowercase - char" )
 {