first commit

extern/stdcxx/4.2.1/examples/manual/generate.cpp

@@ -0,0 +1,96 @@
+/**************************************************************************
+ *
+ * generate.cpp - Example program for initializing a container with values 
+ *                produced by a value-generator class.
+ *
+ * $Id: generate.cpp 648752 2008-04-16 17:01:56Z faridz $
+ *
+ ***************************************************************************
+ *
+ * Licensed to the Apache Software  Foundation (ASF) under one or more
+ * contributor  license agreements.  See  the NOTICE  file distributed
+ * with  this  work  for  additional information  regarding  copyright
+ * ownership.   The ASF  licenses this  file to  you under  the Apache
+ * License, Version  2.0 (the  "License"); you may  not use  this file
+ * except in  compliance with the License.   You may obtain  a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the  License is distributed on an  "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY  KIND, either  express or
+ * implied.   See  the License  for  the  specific language  governing
+ * permissions and limitations under the License.
+ *
+ * Copyright 1994-2006 Rogue Wave Software.
+ * 
+ **************************************************************************/
+
+#include <algorithm>    // for generate, generate_n
+#include <iostream>     // for cout, endl
+#include <iterator>     // for ostream_iterator
+#include <vector>       // for vector
+
+#include <examples.h>
+
+
+// Value generator simply doubles the current value and returns it.
+template <class T>
+class generator
+{
+    T val_;
+public:
+    generator (const T &val) : val_ (val) { }
+    T operator() () {
+        return val_ += val_;
+    }
+};
+
+
+int main ()
+{
+    // Typedef for convenience.
+    typedef std::vector<short, std::allocator<short> > Vector;
+
+    Vector::value_type arr[4] = { 1, 2, 3, 4 };
+
+    // Set up two vectors.
+    Vector v1 (arr, arr + sizeof arr / sizeof *arr);
+    Vector v2 = v1;
+
+    // Set up one empty vector.
+    Vector v3;
+
+    // Create a generator function object.
+    generator<Vector::value_type> gen (1);
+
+    // Generate values for all of v1.
+    std::generate (v1.begin (), v1.end (), gen);
+
+    // Generate values for first 3 of v2.
+    std::generate_n (v2.begin (), 3, gen);
+
+    // Use back_insert_iterator to generate 5 values for v3.
+    std::generate_n (std::back_inserter (v3), 5, gen);
+
+    // Copy all three to cout.
+    std::ostream_iterator<Vector::value_type,
+                          char,
+                          std::char_traits<char> > out (std::cout, " ");
+
+    std::copy (v1.begin (), v1.end (), out);
+    std::cout << std::endl;
+
+    std::copy (v2.begin (), v2.end (), out);
+    std::cout << std::endl;
+
+    std::copy (v3.begin (), v3.end (), out);
+    std::cout << std::endl;
+
+    // Generate 3 values into cout.
+    std::generate_n (out, 3, gen);
+    std::cout << std::endl;
+
+    return 0;
+}