Add support for hex formatting

3 files changed, 13 insertions, 6 deletions

diff --git a/src/highlighters.cc b/src/highlighters.cc
index f1c871d2..cd13daad 100644
--- a/src/highlighters.cc
+++ b/src/highlighters.cc
@@ -17,7 +17,6 @@
 #include "utf8.hh"
 #include "utf8_iterator.hh"
 
-#include <sstream>
 #include <locale>
 
 namespace Kakoune
@@ -834,15 +833,12 @@ void expand_unprintable(const Context& context, HighlightFlags flags, DisplayBuf
                     auto next = utf8::next(it, end);
                     if (cp != '\n' and not iswprint(cp))
                     {
-                        std::ostringstream oss;
-                        oss << "U+" << std::hex << cp;
-                        const auto& stdstr = oss.str();
-                        String str{stdstr.begin(), stdstr.end()};
                         if (it.coord() != atom_it->begin())
                             atom_it = ++line.split(atom_it, it.coord());
                         if (next.coord() < atom_it->end())
                             atom_it = line.split(atom_it, next.coord());
-                        atom_it->replace(str);
+
+                        atom_it->replace(format("U+{}", hex(cp)));
                         atom_it->face = { Color::Red, Color::Black };
                         break;
                     }
diff --git a/src/string.cc b/src/string.cc
index 8d675388..2ed77156 100644
--- a/src/string.cc
+++ b/src/string.cc
@@ -137,6 +137,13 @@ InplaceString<24> to_string(size_t val)
     return res;
 }
 
+InplaceString<24> to_string(Hex val)
+{
+    InplaceString<24> res;
+    res.m_length = sprintf(res.m_data, "%zx", val.val);
+    return res;
+}
+
 InplaceString<24> to_string(float val)
 {
     InplaceString<24> res;
diff --git a/src/string.hh b/src/string.hh
index 5d3855f1..424e994c 100644
--- a/src/string.hh
+++ b/src/string.hh
@@ -270,8 +270,12 @@ struct InplaceString
     char m_data[N];
 };
 
+struct Hex { size_t val; };
+inline Hex hex(size_t val) { return {val}; }
+
 InplaceString<16> to_string(int val);
 InplaceString<24> to_string(size_t val);
+InplaceString<24> to_string(Hex val);
 InplaceString<24> to_string(float val);
 
 template<typename RealType, typename ValueType>