Interval <-> string conversion: std::string operators

Author: SimonRohou

src/arithmetic/ibex_Interval.cpp

@@ -291,18 +291,17 @@ int Interval::diff(const Interval& y, Interval& c1, Interval& c2) const {
 	return res;
 }
 
-Interval::Interval(const std::string& s)
-{
-	if(s.find(EMPTY_SET.str()) != std::string::npos)
+Interval::Interval(const std::string& s) {
+	if(s.find((std::string)EMPTY_SET) != std::string::npos)
 		*this = EMPTY_SET;
 
-	else if(s.find(POS_REALS.str()) != std::string::npos)
+	else if(s.find((std::string)POS_REALS) != std::string::npos)
 		*this = POS_REALS;
 
-	else if(s.find(NEG_REALS.str()) != std::string::npos)
+	else if(s.find((std::string)NEG_REALS) != std::string::npos)
 		*this = NEG_REALS;
 
-	else if(s.find(ALL_REALS.str()) != std::string::npos)
+	else if(s.find((std::string)ALL_REALS) != std::string::npos)
 		*this = ALL_REALS;
 
 	else { // string of the form "[lb, ub]"
@@ -348,10 +347,9 @@ std::ostream& operator<<(std::ostream& os, const Interval& x) {
   return os;
 }
 
-std::string Interval::str(int precision) const
-{
+Interval::operator std::string() const {
 	std::stringstream sstream;
-	sstream << std::setprecision(precision) << *this;
+	sstream << *this;
 	return sstream.str();
 }
 

src/arithmetic/ibex_Interval.h

@@ -508,12 +508,6 @@ class Interval {
      */
     std::pair<Interval,Interval> bisect(double ratio=0.5) const;
 
-    /** \brief String
-     *
-     * Return string stream of \a x with a given precision.
-     */
-    std::string str(int precision = 6) const;
-
     /** \brief pi. */
     static const Interval PI;
     /** \brief 2*pi. */
@@ -544,6 +538,10 @@ class Interval {
      */
     operator const ExprConstant&() const;
 
+    /** \brief Cast the interval into a const std::string
+     */
+    operator std::string() const;
+
 //private:
 #ifdef _IBEX_WITH_GAOL_
     /* \brief Wrap the gaol-interval [x]. */
@@ -951,8 +949,6 @@ inline Interval& Interval::operator=(double x) {
 	return *this;
 }
 
-
-
 inline Interval& Interval::operator=(const Interval& x) {
 	itv = x.itv;
 	return *this;
@@ -969,7 +965,6 @@ inline Interval& Interval::inflate(double delta, double chi) {
 	return *this;
 }
 
-
 inline bool Interval::operator!=(const Interval& x) const {
 	return !(*this==x);
 }
@@ -1207,7 +1202,6 @@ inline bool bwd_atan(const Interval& y,  Interval& x) {
 	return !x.is_empty();
 }
 
-
 inline bool bwd_acosh(const Interval& y,  Interval& x) {
 	if (y.is_empty() || y.ub()<0.0) {
 		x.set_empty(); return false;
@@ -1536,6 +1530,14 @@ inline bool bwd_imod(Interval& x, Interval& y, const double& p) {
     return true;
 }
 
+inline std::string operator+(const std::string& s, const Interval& x) {
+    return s + (std::string)x;
+}
+
+inline std::string operator+(const Interval& x, const std::string& s) {
+    return (std::string)x + s;
+}
+
 } // end namespace ibex
 
 #endif // _IBEX_INTERVAL_H_

tests/TestString.cpp

@@ -10,6 +10,7 @@
  * Updated     : April 18, 2016
  * ---------------------------------------------------------------------------- */
 
+#include <iomanip>
 #include "TestString.h"
 
 using namespace std;
@@ -32,8 +33,21 @@ void TestString::test02() {
 
 bool TestString::testConversion(const Interval& intv, int precision)
 {
-	string intv_string = "  " + intv.str(precision) + "  "; // adding unwanted spaces
-	Interval intv_parsed = Interval(intv_string);
+	return testConversionString(intv) && testConversionOstream(intv, precision);
+}
+
+bool TestString::testConversionString(const Interval& intv)
+{
+	Interval intv_parsed = Interval("  " + intv + "  "); // adding unwanted spaces
+	return intv_parsed == intv ||
+			fabs(intv_parsed.lb() - intv.lb()) < 1.0e-1 && fabs(intv_parsed.ub() - intv.ub()) < 1.0e-1;
+}
+
+bool TestString::testConversionOstream(const Interval& intv, int precision)
+{
+	stringstream sstream;
+	sstream << setprecision(precision) << "  " << intv << "  "; // adding unwanted spaces
+	Interval intv_parsed = Interval(sstream.str());
 	return intv_parsed == intv ||
 			fabs(intv_parsed.lb() - intv.lb()) < 1.0e-1 && fabs(intv_parsed.ub() - intv.ub()) < 1.0e-1;
 }

tests/TestString.h

@@ -39,6 +39,8 @@ class TestString : public CppUnit::TestFixture {
 protected:
 
 	bool testConversion(const Interval& intv, int precision);
+	bool testConversionString(const Interval& intv);
+	bool testConversionOstream(const Interval& intv, int precision);
 };
 
 CPPUNIT_TEST_SUITE_REGISTRATION(TestString);