[cpp.predefined] Make double-underscore names searchable by switching from a

thin space to a kerning gap between the underscores.

Author: zygoloid

source/macros.tex

@@ -211,9 +211,10 @@
 \newcommand{\unspecalloctype}{\UNSP{unspecified allocator type}}
 
 %% Double underscore
-\newcommand{\unun}{\_\,\_}
-\newcommand{\xname}[1]{\unun\,#1}
-\newcommand{\mname}[1]{\tcode{\unun\,#1\,\unun}}
+\newcommand{\ungap}{\kern.5pt}
+\newcommand{\unun}{\_\ungap\_}
+\newcommand{\xname}[1]{\unun\ungap#1}
+\newcommand{\mname}[1]{\tcode{\unun\ungap#1\ungap\unun}}
 
 %% Ranges
 \newcommand{\Range}[4]{\tcode{#1\brk{}#3,\brk{}#4\brk{}#2}\xspace}