0.11.0

Full Changelog

Make library usage more safe to use and add default_context feature

• Rework internal objects' lifetime safety

• Add protection against using nodes from different contexts

• Fix bug where synced event_range based observer callbacks were called
  without events
  if any of signals in dep_pack are changed. It contradicts to a note:
  "Changes of signals in dep_pack do not trigger an update - only received
  events do"

• BREAKING! Change order of dep_pack... args passed in functor passed in process
  adaptor

  ureact::context ctx;
  
  using record_t = std::pair<std::string, int>;
  
  auto src = make_source<int>( ctx );
  auto n = make_var<unsigned>( ctx, {} );
  auto timestamp = make_var<std::string>( ctx, {} );
  ureact::events<record_t> processed;
  
  // Before. Arguments corresponding to dep_pack are placed in the end of argument list
  const auto repeater = []( ureact::event_range<int> range,          // src
                            ureact::event_emitter<record_t> out,
                            unsigned n, const std::string& timestamp // with( n, timestamp )
                          ) {
  };
  
  // After. Arguments corresponding to dep_pack are placed just after event_range,
  // that corresponds to the order of arguments passed to "ureact::process"
  // and matches approach of "synced" versions of other adaptors
  const auto repeater = []( ureact::event_range<int> range,           // src
                            unsigned n, const std::string& timestamp, // with( n, timestamp )
                            ureact::event_emitter<record_t> out
                          ) {
      ...
  };
  
  processed = ureact::process<record_t>( src, with( n, timestamp ), repeater );

• Add default context feature. It is more example friendly and maybe more
  user-friendly in general.
  This feature adds a new namespace ureact::default_context and several new
  functions and classes there:

  • function default_context::get() in ureact/default_context.hpp
  • functions default_context::make_var()
    and default_context::make_const() in ureact/signal.hpp
  • functions default_context::make_source()
    and default_context::make_never() in ureact/events.hpp
  • class default_context::transaction and
    function default_context::do_transaction() in ureact/transaction.hpp

  default_context::get() returns thread_local copy of default context if it
  exists or makes a new one.
  It is mostly intended to be used by other functions and classes
  of default_context instead of direct usage.

  All other functions and classes are just strait up analogs of entities
  outside default_context,
  the only difference - they don't have context arguments, instead they
  use context received from default_context::get().

  Without default_context feature:

  ureact::context ctx;
  
  auto var = ureact::make_var( ctx, 1 );
  auto cst = ureact::make_const( ctx, 2 );
  auto src = ureact::make_source<int>( ctx );
  auto nvr = ureact::make_never<int>( ctx );
  
  do_transaction( ctx, [&](){
      ureact::transaction _( ctx );
      ...
  });

  With default_context feature:

  using namespace ureact::default_context;
  
  auto var = make_var( 1 );
  auto cst = make_const( 2 );
  auto src = make_source<int>();
  auto nvr = make_never<int>();
  
  do_transaction( [&](){
      transaction _;
      ...
  });