Merge pull request #4094 from mjendrusch/cppTemplates

Fixes #4093

compiler/ccgtypes.nim

@@ -654,7 +654,7 @@ proc getTypeDescAux(m: BModule, typ: PType, check: var IntSet): Rope =
       else:
         result = cppName & "<"
         for i in 1 .. typ.len-2:
-          if i > 1: result.add(", ")
+          if i > 1: result.add(" COMMA ")
           result.add(getTypeDescAux(m, typ.sons[i], check))
         result.add("> ")
       # always call for sideeffects:

lib/nimbase.h

@@ -222,6 +222,8 @@ __clang__
 
 /* ----------------------------------------------------------------------- */
 
+#define COMMA ,
+
 #include <limits.h>
 #include <stddef.h>
 

tests/cpp/ttemplatetype.nim

@@ -0,0 +1,9 @@
+type
+  Map {.importcpp: "std::map", header: "<map>".} [T,U] = object
+
+proc cInitMap(T: typedesc, U: typedesc): Map[T,U] {.importcpp: "std::map<'*1,'*2>()", nodecl.}
+
+proc initMap[T, U](): Map[T, U] =
+  result = cInitMap(T, U)
+
+var x: Map[cstring, cint] = initMap[cstring, cint]()