[PATCH] D16467: [libcxx] re.results.form: Format out-of-range subexpression references as null

[Marshall Clow via cfe-commits]

mclow.lists added inline comments.

================
Comment at: include/regex:5390
@@ -5389,3 +5389,3 @@
                     size_t __i = *__fmt_first - '0';
-                    __out = _VSTD::copy(__matches_[__i].first,
-                                       __matches_[__i].second, __out);
+                    if (__i < __matches_.size()) {
+                        __out = _VSTD::copy(__matches_[__i].first,
----------------
A better idea.  
Replace this code:
     __out = _VSTD::copy(__matches_[__i].first, __matches_[__i].second, __out);
with:
     __out = _VSTD::copy((*this)[__i].first, (*this)[__i].second, __out);

`match_results::operator[]` already has the logic to do something with out of range indexes. 


================
Comment at: include/regex:5444
@@ -5441,3 +5443,3 @@
                         }
-                        __out = _VSTD::copy(__matches_[__i].first,
-                                           __matches_[__i].second, __out);
+                        if (__i < __matches_.size()) {
+                            __out = _VSTD::copy(__matches_[__i].first,
----------------
Same as above.

================
Comment at: test/std/re/re.results/re.results.form/form1.pass.cpp:61
@@ +60,3 @@
+        assert(r == out + 54);
+        assert(std::string(out) == "prefix: ab, match: cdefghi, suffix: jk, m[1]: , m[2]: ");
+    }
----------------
Keep the tests.


http://reviews.llvm.org/D16467