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;
+}
+