So, I will try the following compiled code:
#include <math.h> #include <iostream> #include <algorithm> #include <vector> #include "boolinq.h" float dtSqrt(float x) { return sqrtf(x); } /// Returns the distance between two points. /// @param[in] v1 A point. [(x, y, z)] /// @param[in] v2 A point. [(x, y, z)] /// @return The distance between the two points. inline float dtVdist(const float* v1, const float* v2) { const float dx = v2[0] - v1[0]; const float dy = v2[1] - v1[1]; const float dz = v2[2] - v1[2]; return dtSqrt(dx*dx + dy*dy + dz*dz); } int main () { float target[] = {1,2,3}; float floats1[] = {1.321f,2.123f,3.333f}; float floats2[] = {1.011f,2.234f,3.555f}; float floats3[] = {1.9f,2.9f,3.9f}; float floats4[] = {1,2,3}; float floats5[] = {1,2,3.123f}; std::vector<const float *> floatsVector; floatsVector.push_back(floats1); floatsVector.push_back(floats2); floatsVector.push_back(floats3); floatsVector.push_back(floats4); floatsVector.push_back(floats5); //stl way //std::sort(floatsVector.begin(), floatsVector.end(), [&](const float* pointA, const float* pointB) -> bool{ // auto distA = dtVdist(pointA, target); // auto distB = dtVdist(pointB, target); // return distA < distB; //}); // auto stl_point = floatsVector.front(); try { auto point = boolinq::from( floatsVector ) .orderBy([&](const float* point) -> float{ auto dist = dtVdist(point, target); return dist; }) .reverse() .toVector() .front(); std::cout << point[0] << " " << point[1] << " " << point[2] << ";" << std::endl; } catch (std::exception &e) { std::cout << e.what() << std::endl; } std::cin.get(); return 0; }
having a boolinq header , this program runs pretty fast. However, he fails impregnable! at runtime with some error in asserting the inner vector:
problem:
boolinq::from( floatsVector ) .orderBy([&](const float* point) -> float{ auto dist = dtVdist(point, target); return dist; }).toVector();
- empty vector.
uncommenting stl code makes the program work as expected!
further more precise reordering of the point makes it work as expected:
float floats1[] = {1,2,3}; float floats2[] = {1,2,3.123f}; float floats3[] = {1.321f,2.123f,3.333f}; float floats4[] = {1.011f,2.234f,3.555f}; float floats5[] = {1.9f,2.9f,3.9f};
Really strange mistake ...
btw the following code:
#include <math.h> #include <iostream> #include <algorithm> #include <vector> #include "boolinq/boolinq.h" struct Point { float X; float Y; float Z; Point() : X(0), Y(0), Z(0) {} Point(float X, float Y, float Z) : X(X), Y(Y), Z(Z) {} }; float dtSqrt(float x) { return sqrtf(x); } inline float dtVdist(const float* v1, const float* v2) { const float dx = v2[0] - v1[0]; const float dy = v2[1] - v1[1]; const float dz = v2[2] - v1[2]; return dtSqrt(dx*dx + dy*dy + dz*dz); } inline float dtVSqrDist(const Point & v1, const Point & v2) { const float dx = v2.X - v1.X; const float dy = v2.Y - v1.Y; const float dz = v2.Z - v1.Z; return dx*dx + dy*dy + dz*dz; } int main () { auto target = Point(1,2,3); auto pointA = Point(1,-2,3); auto pointB = Point(1,2,3); std::vector<Point> pointsVector; pointsVector.push_back(pointA); pointsVector.push_back(pointB); //stl way std::sort(pointsVector.begin(), pointsVector.end(), [&](const Point & pointA, const Point & pointB) -> bool{ auto distA = dtVSqrDist(pointA, target); auto distB = dtVSqrDist(pointB, target); return distA < distB; }); std::reverse(pointsVector.begin(), pointsVector.end()); auto stl_point = pointsVector.front(); std::cout << "stl point: " << stl_point.X << " " << stl_point.Y << " " << stl_point.Z << ";" << std::endl; //try { auto points = boolinq::from( pointsVector ) .orderBy([&](const Point & point) -> float{ auto dist = dtVSqrDist(point, target); return dist; }) .reverse() .toVector(); auto point = points.empty() ? Point() : points.front(); std::cout << "boolinq point: " << point.X << " " << point.Y << " " << point.Z << ";" << std::endl; //} catch (std::exception &e) { // std::cout << e.what() << std::endl; //} std::cin.get(); return 0; }
It produces:
stl point: 1 -2 3; boolinq point: 0 0 0;
What is wrong with my code? He looks the same. Examples that can be provided on the boolinq main page ...?