Fraction: New ctors accept STL container args

bindings/python/openshot.i

@@ -127,6 +127,8 @@
 
 /* Instantiate the required template specializations */
 %template() std::map<std::string, int>;
+%template() std::pair<int, int>;
+%template() std::vector<int>;
 
 /* Make openshot.Fraction more Pythonic */
 %extend openshot::Fraction {

src/Fraction.cpp

@@ -29,13 +29,23 @@
  */
 
 #include "Fraction.h"
+#include <cmath>
 
 using namespace openshot;
 
-// Constructor
-Fraction::Fraction() :
-	num(1), den(1) {
-}
+// Delegating constructors
+Fraction::Fraction() : Fraction::Fraction(1, 1) {};
+
+Fraction::Fraction(std::pair<int, int> pair)
+	: Fraction::Fraction(pair.first, pair.second) {};
+
+Fraction::Fraction(std::map<std::string, int> mapping)
+	: Fraction::Fraction(mapping["num"], mapping["den"]) {};
+
+Fraction::Fraction(std::vector<int> vector)
+	: Fraction::Fraction(vector[0], vector[1]) {};
+
+// Full constructor
 Fraction::Fraction(int num, int den) :
 	num(num), den(den) {
 }

src/Fraction.h

@@ -31,7 +31,10 @@
 #ifndef OPENSHOT_FRACTION_H
 #define OPENSHOT_FRACTION_H
 
-#include <cmath>
+#include <string>    // for std::string
+#include <utility>   // for std::pair
+#include <map>       // for std::map
+#include <vector>    // for std::vector
 
 namespace openshot {
 
@@ -49,9 +52,19 @@ namespace openshot {
 
 		/// Default Constructor
 		Fraction();
+
 		/// Constructor with numerator and denominator
 		Fraction(int num, int den);
 
+		/// Constructor that accepts a (num, den) pair
+		Fraction(std::pair<int, int> pair);
+
+		/// Constructor that takes a vector of length 2 (containing {num, den})
+		Fraction(std::vector<int> vector);
+
+		/// Constructor that takes a key-value mapping (keys: 'num'. 'den')
+		Fraction(std::map<std::string, int> mapping);
+
 		/// Calculate the greatest common denominator
 		int GreatestCommonDenominator();