ENH: Add assignment operator to KWSys RegularExpression.

Source/kwsys/RegularExpression.cxx

@@ -74,6 +74,38 @@ RegularExpression::RegularExpression (const RegularExpression& rxp) {
   this->regmlen = rxp.regmlen;                  // Copy remaining private data
 }
 
+// operator= -- Copies the given regular expression.
+RegularExpression& RegularExpression::operator= (const RegularExpression& rxp)
+{
+  if ( !rxp.program )
+    {
+    this->program = 0;
+    return *this;
+    }
+  int ind;
+  this->progsize = rxp.progsize;                // Copy regular expression size
+  this->program = new char[this->progsize];     // Allocate storage
+  for(ind=this->progsize; ind-- != 0;)          // Copy regular expresion
+    this->program[ind] = rxp.program[ind];
+  this->startp[0] = rxp.startp[0];              // Copy pointers into last
+  this->endp[0] = rxp.endp[0];                  // Successful "find" operation
+  this->regmust = rxp.regmust;                  // Copy field
+  if (rxp.regmust != 0) {
+    char* dum = rxp.program;
+    ind = 0;
+    while (dum != rxp.regmust) {
+      ++dum;
+      ++ind;
+    }
+    this->regmust = this->program + ind;
+  }
+  this->regstart = rxp.regstart;                // Copy starting index
+  this->reganch = rxp.reganch;                  // Copy remaining private data
+  this->regmlen = rxp.regmlen;                  // Copy remaining private data
+
+  return *this;
+}
+
 // operator== -- Returns true if two regular expressions have the same
 // compiled program for pattern matching.
 bool RegularExpression::operator== (const RegularExpression& rxp) const {

Source/kwsys/RegularExpression.hxx.in

@@ -233,6 +233,11 @@ public:
    */
   inline kwsys_stl::string::size_type end() const;
 
+  /**
+   * Copy the given regular expression.
+   */
+  RegularExpression& operator= (const RegularExpression& rxp);
+
   /**
    * Returns true if two regular expressions have the same
    * compiled program for pattern matching.