[Boost-commit] svn:boost r69835 - branches/msm/v2_30/libs/msm/example

Subject: [Boost-commit] svn:boost r69835 - branches/msm/v2_30/libs/msm/example
From: christophe.j.henry_at_[hidden]
Date: 2011-03-10 17:44:22

Author: chenry
Date: 2011-03-10 17:44:19 EST (Thu, 10 Mar 2011)
New Revision: 69835
URL: http://svn.boost.org/trac/boost/changeset/69835

Log:
added first example
Added:
   branches/msm/v2_30/libs/msm/example/lambda.cpp   (contents, props changed)

Added: branches/msm/v2_30/libs/msm/example/lambda.cpp
==============================================================================
--- (empty file)
+++ branches/msm/v2_30/libs/msm/example/lambda.cpp	2011-03-10 17:44:19 EST (Thu, 10 Mar 2011)
@@ -0,0 +1,115 @@
+
+#include <iostream>
+#include <algorithm>
+#include <vector>
+#include <set>
+#include <boost/msm/lpp/lpp.hpp>
+#include <boost/assert.hpp>
+
+namespace mpl = boost::mpl;
+namespace proto = boost::proto;
+namespace fusion = boost::fusion;
+
+using namespace boost::msm::lpp;
+
+int foo(int p){return p+1;}
+int foo(){return 0;}
+
+BOOST_MSM_LPP_FUNCTION(foo_,foo)
+
+
+
+int main()
+{
+
+    // 1. STL type definition
+    std::set<int, BOOST_MSM_LPP_LAMBDA_EXPR(_1 < _2) > s2;
+    // same as
+    std::set<int, BOOST_TYPEOF( Lambda()(_1 < _2) ) > s;
+
+    // 2. simple STL algorithm
+    std::vector<int> vec(12);
+    std::transform(vec.begin(),vec.end(),vec.begin(),lambda[ ++_1] );
+    BOOST_ASSERT(vec[10] == 1);
+
+    // 3. sequence of statements ++_1; ++_1; return ++_1
+    std::transform(vec.begin(),vec.end(),vec.begin(),lambda[ ++_1, ++_1 , ++_1 ] );
+    BOOST_ASSERT(vec[10] == 4);
+
+    // 4. More complicated, and return value is the last statement called
+    std::transform(vec.begin(),vec.end(),vec.begin(),
+        lambda[ if_(_1)[ ++_1, ++_1 ] /*else */  [ ++_1 ]  ] );
+    BOOST_ASSERT(vec[10] == 6);
+
+    // 5. a taste of 0x: capturing
+    int q=4;
+    std::transform(vec.begin(),vec.end(),vec.begin(),lambda[_params << q ][ _c1 + _1] );
+    BOOST_ASSERT(vec[10] == 10); // was 6, now 6+4
+
+    // 5.1 capturing by value (_c1 not modified)
+    std::transform(vec.begin(),vec.end(),vec.begin(),lambda[_params << q ][ ++_c1 ] );
+    BOOST_ASSERT(vec[10] == 5); //always 4+1
+   
+    // 5.2 capturing by ref (_c1 modified at each call)
+    int p=0;
+    std::transform(vec.begin(),vec.end(),vec.begin(),lambda[_params << boost::ref(p) ][ _c1++ ] );
+    BOOST_ASSERT(vec[0] == 0);
+    BOOST_ASSERT(vec[1] == 1);
+    BOOST_ASSERT(vec[2] == 2);
+
+    // 5.3 capturing by cref
+    //this will correctly will not compile (const)
+    //std::transform(vec.begin(),vec.end(),vec.begin(),lambda[_params << boost::cref(p) ][ _c1++ ] );
+    // this will: _c1 not modified
+    std::transform(vec.begin(),vec.end(),vec.begin(),lambda[_params << boost::cref(q) ][ _1 + _c1 ] );
+    BOOST_ASSERT(vec[1] == 5); // 1 + 4
+
+    // 6. using user functions
+    // int foo(int p){return p+1;}
+    std::transform(vec.begin(),vec.end(),vec.begin(),lambda[ _1 + foo_(_1)] );
+    BOOST_ASSERT(vec[1] == 11); // 5 from before + (5+1)
+
+    std::transform(vec.begin(),vec.end(),vec.begin(),vec.begin(),lambda[_params << 4 ][ foo_(_1 + _c1) ] );
+    BOOST_ASSERT(vec[1] == 16); // foo(11 + 4)
+
+    // 7.  a bit of everything ;-)
+
+    // 2nd form of transform
+    std::transform(vec.begin(),vec.end(),vec.begin(),vec.begin(),lambda[_params << 2 ][ (_1 + _2) * _c1] );
+    BOOST_ASSERT(vec[1] == 64); // (16+16)*2
+
+    // if clause executing 2 statements, returning the second one (not C++ ;-) )
+    vec[1] = 1;
+    std::for_each(vec.begin(),vec.end(),lambda[ if_((++_1,_1>=_1)) /* then */ [++_1] ] );
+    BOOST_ASSERT(vec[1] == 3); // 1 + if(++_1, true) then ++_1 => 1 + 1 + 1 
+
+    // completely useless but so fun :)
+    vec[1] = 1;
+    std::transform(vec.begin(),vec.end(),vec.begin(),lambda[_params << 10 ]
+        [ 
+            if_(_1) /* true */
+            [
+                if_(_1 + _c1) /* true */
+                [
+                    ++_1,++_1 /* _1+2 */
+                ]
+                /* else */
+                [
+                    --_1
+                ] 
+            ]
+            /* else */
+            [
+                --_1,--_1
+            ] 
+        ] );
+
+    BOOST_ASSERT(vec[1] == 3); // 1 + 2
+
+    std::cout << "we survived all this :)" << std::endl;
+    // note: On a Q6600, compiles in:
+    // 9s with VC9
+    // 8.6 with g++ 4.4 MinGW
+    return 0;
+}
+