151 lines
4.2 KiB
C++
151 lines
4.2 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
|
|
|
|
|
|
/** @file try.cpp
|
|
** How to build generic string conversion into `ostream::operator<< `.
|
|
**
|
|
*/
|
|
|
|
typedef unsigned int uint;
|
|
|
|
#include "lib/p.hpp"
|
|
//#include "lib/format-util.hpp"
|
|
#include "lib/diff/gen-node.hpp"
|
|
//#include "lib/util.hpp"
|
|
|
|
#include "lib/meta/util.hpp"
|
|
|
|
#include <iostream>
|
|
//#include <cstdarg>
|
|
#include <utility>
|
|
#include <string>
|
|
//#include <typeinfo>
|
|
|
|
using lib::diff::GenNode;
|
|
using lib::P;
|
|
using lib::meta::can_convertToString;
|
|
|
|
//using util::unConst;
|
|
using std::string;
|
|
using std::cout;
|
|
using std::endl;
|
|
|
|
class Reticent
|
|
{
|
|
uint neigh_ = 42;
|
|
};
|
|
|
|
template<typename X, typename...ARGS>
|
|
inline P<X>
|
|
newP (ARGS&&... ctorArgs)
|
|
{
|
|
return P<X>{new X {std::forward<ARGS>(ctorArgs)...}};
|
|
}
|
|
|
|
/////////////////////////////////////////planned for meta/util.hpp
|
|
template <bool B, class T = void>
|
|
struct enable_if_c {
|
|
typedef T type;
|
|
};
|
|
|
|
template <class T>
|
|
struct enable_if_c<false, T> {};
|
|
|
|
template <class Cond, class T = void>
|
|
using enable_if = typename enable_if_c<Cond::value, T>::type;
|
|
|
|
template <class Cond, class T = void>
|
|
using disable_if = typename enable_if_c<not Cond::value, T>::type;
|
|
|
|
/////////////////////////////////////////planned for meta/util.hpp
|
|
|
|
|
|
///////////////////////////////copied from format-util.hpp
|
|
template<typename TY>
|
|
inline string
|
|
typeStr (const TY* obj=0)
|
|
{
|
|
auto mangledType = obj? typeid(obj).name()
|
|
: typeid(TY).name();
|
|
return string("«")+ mangledType +"»";
|
|
}
|
|
|
|
template<typename TY>
|
|
inline string
|
|
typeStr (TY const& ref)
|
|
{ return typeStr(&ref); }
|
|
|
|
|
|
template<typename X, typename COND =void>
|
|
struct CustomStringConv
|
|
{
|
|
static string invoke (X const& x) { return typeStr(x); }
|
|
};
|
|
|
|
template<typename X>
|
|
struct CustomStringConv<X, enable_if<can_convertToString<X>> >
|
|
{
|
|
static string
|
|
invoke (X const& val)
|
|
try { return string(val); }
|
|
catch(...) { return ""; }
|
|
};
|
|
|
|
///////////////////////////////copied from format-util.hpp
|
|
|
|
|
|
template<typename X>
|
|
inline string
|
|
stringz (P<X> ptr)
|
|
{
|
|
if (not ptr)
|
|
return "P"+typeStr(ptr.get())+"{ null }";
|
|
else
|
|
return CustomStringConv<X>::invoke (*ptr);
|
|
}
|
|
|
|
|
|
int
|
|
main (int, char**)
|
|
{
|
|
auto psss = newP<Reticent>();
|
|
auto gnng = newP<GenNode>("Hui", "Buh");
|
|
|
|
cout << "uiii..." << stringz(psss) <<endl;
|
|
cout << "maui..." << stringz(gnng) <<endl;
|
|
|
|
cout << "\n.gulp.\n";
|
|
|
|
return 0;
|
|
}
|