probe
C++ type to aid unit testing of memory leaks/moves/copies inside of containers
For full API info, check the source file.
Example
This shows how the probe is used to inspect what an std::vector is doing to the contents
#include "include/probe.hpp"
#include <vector>
#include <iostream>
#include <cassert>
int main()
{
using probe = pr::probe_t<int>; //we want to use it with ints as underlying values
probe::reset(); //resets all metrics that is stored in class static storage
std::vector<probe> numbers;
numbers.push_back({});
assert(numbers.back() == 0); //can be converted back to value
pr::probe_counts c = probe::last(); //returns all counts of events happened since last time last()/reset() was called
assert(c.copies == 0); //that should not have invoked copies
assert(c.moves > 0); //that should have invoked moves
//print all events as text
std::cout << "after push_back:\n" + to_string(c) << "\n\n";
numbers.emplace_back();
{
probe p = std::move(numbers[0]);
}
pr::probe_state s = probe::state();
assert(s.existing == 2); //2 instances should be existing at this point (has active lifetime. ends with destructor)
assert(s.active == 1); //1 instance should be active at this point (holds meaningful value. ends by being moved from, or destructed)
c = probe::last();
std::cout << "after emplace_back:\n" + to_string(c) << "\n\n";
numbers.insert(numbers.begin(), probe{});
c = probe::last();
std::cout << "after insert:\n" + to_string(c) << "\n\n";
numbers.pop_back();
c = probe::last();
assert(c.destr == 1); //should have called 1 destructor
std::cout << "after pop_back:\n" + to_string(c) << "\n\n";
numbers.clear();
c = probe::last();
std::cout << "after clear:\n" + to_string(c) << "\n\n";
assert(probe::clean()); //clean returns true if there are exactly 0 `existing` and `active` items. i.e. no leaks nor double deletes
//prints a summary of the current state
std::cout << "final report:\n" << probe::report() << "\n";
}Possible output
after push_back:
-calls-
default constructor: 1
value constructor: 0
copy constructor: 0
move constructor: 1
copy assignment: 0
move assignment: 0
destructor: 1
-semantics-
copies: 0
moves: 1
-min/max-
min active: 0
max active: 1
min existing: 0
max existing: 2
after emplace_back:
-calls-
default constructor: 1
value constructor: 0
copy constructor: 0
move constructor: 2
copy assignment: 0
move assignment: 0
destructor: 2
-semantics-
copies: 0
moves: 2
-min/max-
min active: 0
max active: 2
min existing: 0
max existing: 3
after insert:
-calls-
default constructor: 1
value constructor: 0
copy constructor: 0
move constructor: 3
copy assignment: 0
move assignment: 0
destructor: 3
-semantics-
copies: 0
moves: 3
-min/max-
min active: 0
max active: 2
min existing: 0
max existing: 6
after pop_back:
-calls-
default constructor: 0
value constructor: 0
copy constructor: 0
move constructor: 0
copy assignment: 0
move assignment: 0
destructor: 1
-semantics-
copies: 0
moves: 0
-min/max-
min active: 0
max active: 1
min existing: 0
max existing: 2
after clear:
-calls-
default constructor: 0
value constructor: 0
copy constructor: 0
move constructor: 0
copy assignment: 0
move assignment: 0
destructor: 2
-semantics-
copies: 0
moves: 0
-min/max-
min active: 0
max active: 0
min existing: 0
max existing: 1
final report:
===LAST===
-calls-
default constructor: 0
value constructor: 0
copy constructor: 0
move constructor: 0
copy assignment: 0
move assignment: 0
destructor: 0
-semantics-
copies: 0
moves: 0
-min/max-
min active: 0
max active: 0
min existing: 0
max existing: 0
===TOTAL===
-calls-
default constructor: 3
value constructor: 0
copy constructor: 0
move constructor: 6
copy assignment: 0
move assignment: 0
destructor: 9
-semantics-
copies: 0
moves: 6
-min/max-
min active: 0
max active: 2
min existing: 0
max existing: 6
===STATE===
active: 0
existing: 0