I have something like below, but unable to compile it. I don’t get it why I can’t have different type when my variable can hold different types? My code: #include <boost/variant.hpp> #include <iostream> typedef boost::variant<int, float, double, std::string> MultiType; int main() { int a = 1; std::string b = "b"; bool c = true; MultiType… Read More why can't use ternary operator with different types when boost variable can hold multiple types?

I have a boost::geometry::model::polygon<Point> Algorithm::poly and i’m looking for the area of the polygon with area = bg::area(poly); the result is 1.10434e+08 When i’m reading the documentation, i can see "The units are the square of the units used for the points defining the surface". I really don’t understand what it means. https://www.boost.org/doc/libs/1_65_0/libs/geometry/doc/html/geometry/reference/algorithms/area/area_1.html I would… Read More Area of Boost c++ in Square Meters

Consider: #include <boost/any.hpp> #include <iostream> #include <vector> #include <string> int main() { //Code snippet 1 boost::any variable(std::string("Hello ")); std::string* string_ptr_any = boost::any_cast<std::string>(&variable); std::cout << "Pointer value is " << string_ptr_any <<", variable’s address is " << &variable << std::endl; //End Code snippet 1 //Code snippet 2 std::string normalstring = "hello_normal"; std::string* normalstringptr = &normalstring; std::cout… Read More Taking the address of a boost::any variable

I’m trying to use boost::circular_buffer to manage fixed size of the queue. To do that, I wrap boost::circular_buffer by using class Something. class Something { public: Something(); private: boost::circular_buffer<int> buffer; }; Here, the problem is that class Something should wrap iterator of buffer. For example, If I use std::vector<int>, it is simple: class Something {… Read More How to wrap iterator of boost::circular_buffer?

I’m trying to serialize some structs to XML using Boost. I can’t change the structs, so I’m trying to do it non invasively. Following the simple "non intrusive version" example in the docs I managed to get flat text serialization to work. However when I try to extend it to XML by looking at the… Read More Build error serializing struct to XML using Boost

I’m trying to create a std::unordered_map with a boost::variant as a key and with integer value. What I’m trying to make work is this: #include <boost/variant.hpp> #include <unordered_map> #include <string> enum Token {}; struct AssignExpr; struct LiteralExpr; using Expr = boost::variant<boost::blank, boost::recursive_wrapper<AssignExpr>, boost::recursive_wrapper<LiteralExpr>>; using Literal = int; struct LiteralExpr { Literal literal; explicit LiteralExpr(const Literal… Read More Using boost::recursive_variant with std::unordered_map