cpp lexer: add y/d chrono literals, add std::complex literals, fix ch…

…rono literals with digit separator (rouge-ruby#1665)

Co-authored-by: Stuart <stuart.wheaton@jhuapl.edu>

lib/rouge/lexers/cpp.rb

@@ -59,7 +59,7 @@ def self.reserved
       prepend :statements do
         rule %r/(class|struct)\b/, Keyword, :classname
         rule %r/template\b/, Keyword, :template
-        rule %r/\d+(\.\d+)?(?:h|(?:min)|s|(?:ms)|(?:us)|(?:ns))/, Num::Other
+        rule %r/#{dq}(\.#{dq})?(?:y|d|h|(?:min)|s|(?:ms)|(?:us)|(?:ns)|i|(?:if)|(?:il))\b/, Num::Other
         rule %r((#{dq}[.]#{dq}?|[.]#{dq})(e[+-]?#{dq}[lu]*)?)i, Num::Float
         rule %r(#{dq}e[+-]?#{dq}[lu]*)i, Num::Float
         rule %r/0x\h('?\h)*[lu]*/i, Num::Hex

spec/visual/samples/cpp

@@ -18,14 +18,24 @@ char16_t raw_str3[] = uR"(\w+ \d+)";
 // time literal
 #include <chrono>
 using namespace std::chrono_literals;
+auto oneDecade = 10y;
+auto oneYear = 365.2'425d;
 auto oneDay = 24h;
 auto halfAnHour = 30min;
+auto oneYearInMins = 525'949.2min;
 auto halfAnHour = 0.5h;
 auto oneMin = 60s;
 auto oneSec = 1000ms;
 auto oneMilliSec = 1000us;
 auto oneMicroSec = 1000ns;
 
+// complex literal
+#include <complex>
+using namespace std::complex_literals;
+auto complexNumber = 1 + 1i;
+auto complexNumberl = 1 + 1il;
+auto complexNumberf = 1 + 1if;
+
 // null pointer
 int *a = nullptr;