d_rive
Compile time math expressions with c++17.
- standard math addition, subtraction, multiplication, division
- sin, cos, pow, ln, sign, abs, max and min
- derivation
- integration
Check example1.cpp and exampleQuat.cpp for more exciting examples..
To try the examples use a modern compiler and compile the .cpp file g++ -std=c++17 example.cpp.
Examples
(Assume you have using namespace d_rive set)
Lets start with something simple, a constant. Constant have to be written
with the _c suffix. that allows us to do everything at compile time. (f() = 5)
auto f = 5_c;
std::cout << f << "\n";
std::cout << f() << "\n";
Lets define a polynomial and print the polynomial (f(x) = x² + 2x + 3)
auto f = x<0>*x<0> + 2_c * x<0> + 3_c;
std::cout << f << "\n";
Now lets evaluate it with 5 as x<0> (f(x) = x² + 2x + 3):
auto f = x<0>*x<0> + 2_c * x<0> + 3_c;
std::cout << f(5) << "\n";
Easy, right? But what if we need the derivative? (f2 = f')
auto f2 = derive(f);
std::cout << f2 << "\n";
std::cout << f2(5) << "\n";
Derivative of derivates is also possible (f3 = f2')
auto f3 = derive(f2);
std::cout << f3 << "\n";
Integrating? (F' = f)
auto F = integrate(f);
std::cout << F << "\n";
std::cout << F(5) << "\n";
Compile time roots? (sqrt(2))
std::cout << (2_c^0.5_c) << "\n";
Multiple variables: (f(x0, x1, x2) = x0*x1 + x2)
auto f = x<0>*x<1> + x<2>;
std::cout << f(1, 2, 3) << "\n";
std::cout << f << "\n";
std::cout << derive(f, x<1>) << "\n"; // derives for x<1> instead x<0>
Lets go crazy:
auto f = 10_c + ((3_c * x<0>) ^ (0.5_c * x<1> * x<2> - x<1>));
std::cout << derive(f, x<0>) << "\n";
std::cout << derive(f, x<1>) << "\n";
std::cout << derive(f, x<2>) << "\n";
std::cout << integrate(f, x<0>) << "\n";
std::cout << integrate(f, x<1>) << "\n";
std::cout << integrate(f, x<2>) << "\n";