Update testtokenize.cpp

Author: chrchr-github

test/testtokenize.cpp

@@ -6634,7 +6634,9 @@ class TestTokenizer : public TestFixture {
         ASSERT_EQUALS("double&(4[", testAst("void f(double(&)[4]) {}"));
         ASSERT_EQUALS("voidu*", testAst("int* g ( void* (f) (void*), void* u);")); // #12475
         ASSERT_EQUALS("f::(", testAst("::f();")); // #12544
-        ASSERT_EQUALS("(( (, f ({ (= (. c x) 0))))", testAst("f(c, { .x = 0 });", AstStyle::Z3)); // #12806
+        ASSERT_EQUALS("(( f (, c ({ (= (. x) 0))))", testAst("f(c, { .x = 0 });", AstStyle::Z3)); // #12806
+        ASSERT_EQUALS("(= it (( (. s insert) (, it ({ (, (, (= (. a) i) (= (. b) 2)) (= (. c) 3))))))",
+                      testAst("it = s.insert(it, { .a = i, .b = 2, .c = 3 });", AstStyle::Z3)); // #12815
     }
 
     void asttemplate() { // uninstantiated templates will have <,>,etc..