LUMIERA.clone/research/try.cpp

116 lines
4.3 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 - build tuple from runtime-typed variant container
// 3/17 - generic function signature traits, including support for Lambdas
// 9/17 - manipulate variadic templates to treat varargs in several chunks
// 11/17 - metaprogramming to detect the presence of extension points
// 11/17 - detect generic lambda
// 12/17 - investigate SFINAE failure. Reason was indirect use while in template instantiation
// 03/18 - Dependency Injection / Singleton initialisation / double checked locking
/** @file try.cpp
** Rework of the template lib::Depend for singleton and service access.
** The (now for the third time rewritten) dependency factory can be configured to yield
** a subclass singleton, or to bind to an external service. Lazy initialisation relies on
** Double Checked Locking, which we need switch to C++11 Atomics in order to be correct
** (in theory). The impact of this initialisation guard should be investigated by benchmark.
*/
typedef unsigned int uint;
#include "lib/format-cout.hpp"
#include "lib/depend2.hpp"
#include "lib/depend-inject.hpp"
//#include "lib/meta/util.hpp"
#include "lib/test/test-helper.hpp"
#include "lib/util.hpp"
#define SHOW_TYPE(_TY_) \
cout << "typeof( " << STRINGIFY(_TY_) << " )= " << lib::meta::typeStr<_TY_>() <<endl;
#define SHOW_EXPR(_XX_) \
cout << "Probe " << STRINGIFY(_XX_) << " ? = " << _XX_ <<endl;
namespace error = lumiera::error;
using lib::Depend;
using lib::DependInject;
//////////////////////////////////////////////////////////////////////////Microbenchmark
#include "lib/test/microbenchmark.hpp"
using lib::test::microbenchmark;
//////////////////////////////////////////////////////////////////////////(End)Microbenchmark
#include "include/lifecycle.h"
#include "lib/test/testoption.hpp"
#include "lib/test/suite.hpp"
using lumiera::LifecycleHook;
using lumiera::ON_GLOBAL_INIT;
using lumiera::ON_GLOBAL_SHUTDOWN;
///////////////////////////////////////////////////////Usage
class BlackHoleService
: util::NonCopyable
{
volatile int theHole_ = rand() % 1000;
public:
int readMe() { return theHole_; }
};
int
main (int, char**)
{
std::srand(std::time(nullptr));
LifecycleHook::trigger (ON_GLOBAL_INIT);
Depend<BlackHoleService> mystery;
cout << microbenchmark<1> ([&]()
{
0 == mystery().readMe();
}
,5000000000)
<< endl;
LifecycleHook::trigger (ON_GLOBAL_SHUTDOWN);
// cout << "\n.gulp.\n";
return 0;
}