Support o3tl::iterateCodePoints with both sal_Int32 and std::size_t

...and clean up the most gross casting offenses

Change-Id: If0d646fb3e73e71a9a2735569395034973563a1f
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/164602
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <stephan.bergmann@allotropia.de>

comphelper/source/misc/string.cxx

@@ -266,7 +266,7 @@ sal_Int32 getTokenCount(std::u16string_view rIn, sal_Unicode cTok)
 sal_uInt32 decimalStringToNumber(std::u16string_view str)
 {
     sal_uInt32 result = 0;
-    for( sal_Int32 i = 0; i < static_cast<sal_Int32>(str.size()); )
+    for( std::size_t i = 0; i < str.size(); )
     {
         sal_uInt32 c = o3tl::iterateCodePoints(str, &i);
         sal_uInt32 value = 0;

configmgr/source/access.cxx

@@ -20,6 +20,7 @@
 #include <sal/config.h>
 
 #include <cassert>
+#include <cstddef>
 #include <cstdlib>
 #include <utility>
 #include <vector>
@@ -111,7 +112,7 @@ namespace {
 // surrogates, even though they should not appear in well-formed UNO OUString
 // instances anyway), or is a slash (as it causes problems in path syntax):
 bool isValidName(std::u16string_view name, bool setMember) {
-    for (sal_Int32 i = 0; i != static_cast<sal_Int32>(name.size());) {
+    for (std::size_t i = 0; i != name.size();) {
         sal_uInt32 c = o3tl::iterateCodePoints(name, &i);
         if ((c < 0x20 && !(c == 0x09 || c == 0x0A || c == 0x0D))
             || rtl::isSurrogate(c) || c == 0xFFFE || c == 0xFFFF

include/o3tl/string_view.hxx

@@ -15,6 +15,7 @@
 #include <cstddef>
 #include <string>
 #include <string_view>
+#include <type_traits>
 
 #include <o3tl/intcmp.hxx>
 #include <rtl/character.hxx>
@@ -509,8 +510,9 @@ inline double toDouble(std::string_view str)
 }
 
 // Like OUString::iterateCodePoints, but for std::string_view:
-inline sal_uInt32 iterateCodePoints(std::u16string_view string, sal_Int32* indexUtf16,
-                                    sal_Int32 incrementCodePoints = 1)
+template <typename T>
+requires(std::is_same_v<T, sal_Int32> || std::is_same_v<T, std::size_t>) sal_uInt32
+    iterateCodePoints(std::u16string_view string, T* indexUtf16, sal_Int32 incrementCodePoints = 1)
 {
     std::size_t n;
     char16_t cu;

tools/source/misc/json_writer.cxx

@@ -10,6 +10,7 @@
 #include <tools/json_writer.hxx>
 #include <o3tl/string_view.hxx>
 #include <stdio.h>
+#include <cstddef>
 #include <cstring>
 #include <rtl/math.hxx>
 
@@ -137,8 +138,8 @@ void JsonWriter::writeEscapedOUString(std::u16string_view rPropVal)
     ++mPos;
 
     // Convert from UTF-16 to UTF-8 and perform escaping
-    sal_Int32 i = 0;
-    while (i < static_cast<sal_Int32>(rPropVal.size()))
+    std::size_t i = 0;
+    while (i < rPropVal.size())
     {
         sal_uInt32 ch = o3tl::iterateCodePoints(rPropVal, &i);
         if (writeEscapedSequence(ch, mPos))