Compute num_captures_ eagerly.

Change-Id: I7f77eece4c553956e61c746a77c72e095fb1d0e5
Reviewed-on: https://code-review.googlesource.com/c/36874
Reviewed-by: Paul Wankadia <junyer@google.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/re2/re2.h b/re2/re2.h
index c93de56..f846029 100644
--- a/re2/re2.h
+++ b/re2/re2.h
@@ -479,7 +479,7 @@ class RE2 {
   // Return the number of capturing subpatterns, or -1 if the
   // regexp wasn't valid on construction.  The overall match ($0)
   // does not count: if the regexp is "(a)(b)", returns 2.
-  int NumberOfCapturingGroups() const;
+  int NumberOfCapturingGroups() const { return num_captures_; }
 
   // Return a map from names to capturing indices.
   // The map records the index of the leftmost group
@@ -744,6 +744,7 @@ class RE2 {
   re2::Regexp*  entire_regexp_;    // parsed regular expression
   re2::Regexp*  suffix_regexp_;    // parsed regular expression, prefix removed
   re2::Prog*    prog_;             // compiled program for regexp
+  int           num_captures_;     // Number of capturing groups
   bool          is_one_pass_;      // can use prog_->SearchOnePass?
 
   mutable re2::Prog*     rprog_;         // reverse program for regexp
@@ -751,7 +752,6 @@ class RE2 {
                                          // (or points to empty string)
   mutable ErrorCode      error_code_;    // Error code
   mutable string         error_arg_;     // Fragment of regexp showing error
-  mutable int            num_captures_;  // Number of capturing groups
 
   // Map from capture names to indices
   mutable const std::map<string, int>* named_groups_;
@@ -761,7 +761,6 @@ class RE2 {
 
   // Onces for lazy computations.
   mutable std::once_flag rprog_once_;
-  mutable std::once_flag num_captures_once_;
   mutable std::once_flag named_groups_once_;
   mutable std::once_flag group_names_once_;