lumiera_/research/try.cpp

95 lines
3.1 KiB
C++

/* try.cpp - for trying out some language features....
* scons will create the binary bin/try
*
*/
// 8/07 - how to control NOBUG??
// execute with NOBUG_LOG='ttt:TRACE' bin/try
// 1/08 - working out a static initialisation problem for Visitor (Tag creation)
// 1/08 - check 64bit longs
// 4/08 - comparison operators on shared_ptr<Asset>
// 4/08 - conversions on the value_type used for boost::any
// 5/08 - how to guard a downcasting access, so it is compiled in only if the involved types are convertible
// 7/08 - combining partial specialisation and subclasses
// 10/8 - abusing the STL containers to hold noncopyable values
// 6/09 - investigating how to build a mixin template providing an operator bool()
// 12/9 - tracking down a strange "warning: type qualifiers ignored on function return type"
// 1/10 - can we determine at compile time the presence of a certain function (for duck-typing)?
// 4/10 - pretty printing STL containers with python enabled GDB?
// 1/11 - exploring numeric limits
// 1/11 - integer floor and wrap operation(s)
// 1/11 - how to fetch the path of the own executable -- at least under Linux?
// 10/11 - simple demo using a pointer and a struct
// 11/11 - using the boost random number generator(s)
// 12/11 - how to detect if string conversion is possible?
// 1/12 - is partial application of member functions possible?
// 5/14 - c++11 transition: detect empty function object
// 7/14 - c++11 transition: std hash function vs. boost hash
// 9/14 - variadic templates and perfect forwarding
// 11/14 - pointer to member functions and name mangling
// 8/15 - Segfault when loading into GDB (on Debian/Jessie 64bit
// 8/15 - generalising the Variant::Visitor
// 1/16 - generic to-string conversion for ostream
// 1/16 - generate receiver function with arbitrary arguments
/** @file try.cpp
** Metaprogramming: how to generate a function to accept a fixed set
** of typed arguments, where the sequence of arguments is given as type sequence
** or as variadic parameter pack. Also how to bind concrete argument values to
** such a function, where the concrete arguments come as runtime collection
** of variant holders.
**
*/
typedef unsigned int uint;
//#include "lib/diff/gen-node.hpp"
#include "lib/time/timevalue.hpp"
#include "lib/format-cout.hpp"
#include "lib/format-util.hpp"
#include <functional>
#include <vector>
#include <string>
//using lib::diff::GenNode;
using lib::time::Time;
using util::stringify;
using util::join;
using std::function;
using std::vector;
using std::string;
using VecS = vector<string>;
template<typename...ARGS>
string
operate (ARGS const& ...args)
{
VecS strs = stringify<VecS> (args...);
return join (strs);
}
int
main (int, char**)
{
cout << operate ("lalü", string("lala"), 12, 34L, 56.78) <<endl;
function<string(double, Time)> funny;
cout << "funny? " << bool(funny) <<endl;
funny = operate<double,Time>;
cout << "funny? " << bool(funny) <<endl;
cout << funny(98.7654321987654321987654321, Time(1,2,3,4)) <<endl;
cout << "\n.gulp.\n";
return 0;
}