7 files changed, 191 insertions, 0 deletions
diff --git a/graphs/cpp/cartesian_vector/format_numerical_data.cc b/graphs/cpp/cartesian_vector/format_numerical_data.cc
new file mode 100644
index 0000000..b6355d2
--- /dev/null
+++ b/graphs/cpp/cartesian_vector/format_numerical_data.cc
@@ -0,0 +1,13 @@
+#include "format_numerical_data.hh"
+std::ostream& FormatNumericalData::formatOs(std::ostream& os) const
+{
+    if (precision >= 0)
+    {
+        os.precision(precision);
+    }
+    if (scientific_notation)
+        std::scientific(os);
+    if (display_plus)
+        std::showpos(os);
+    return os;
+}
+\ No newline at end of file
diff --git a/graphs/cpp/cartesian_vector/format_numerical_data.hh b/graphs/cpp/cartesian_vector/format_numerical_data.hh
new file mode 100644
index 0000000..359e297
--- /dev/null
+++ b/graphs/cpp/cartesian_vector/format_numerical_data.hh
@@ -0,0 +1,22 @@
+#pragma once
+
+#include <ostream>
+#include <string>
+
+struct FormatNumericalData
+{
+    //! string to be printed before the data
+    std::string prefix;
+    //! string to be printed after the data
+    std::string suffix;
+    //! gives the minimum number of digits to appear (after the radix if
+    //! scientific_notation is enabled)
+    int precision = -1;
+    //! define if scientific notation is enabled
+    bool scientific_notation = false;
+    //! define if a sign + should be placed before a number
+    bool display_plus = false;
+
+    //! format the given stream according to class attributes
+    std::ostream& formatOs(std::ostream& os) const;
+};
diff --git a/graphs/cpp/cartesian_vector/state_saver.cc b/graphs/cpp/cartesian_vector/state_saver.cc
new file mode 100644
index 0000000..4b4a244
--- /dev/null
+++ b/graphs/cpp/cartesian_vector/state_saver.cc
@@ -0,0 +1,11 @@
+#include "state_saver.hh"
+StateSaver::StateSaver(std::ostream& os)
+    : saved_stream_{ os }
+    , saved_flags_{ os.flags() }
+    , saved_precision_{ os.precision() }
+{}
+StateSaver::~StateSaver()
+{
+    saved_stream_.flags(saved_flags_);
+    saved_stream_.precision(saved_precision_);
+}
+\ No newline at end of file
diff --git a/graphs/cpp/cartesian_vector/state_saver.hh b/graphs/cpp/cartesian_vector/state_saver.hh
new file mode 100644
index 0000000..f52127c
--- /dev/null
+++ b/graphs/cpp/cartesian_vector/state_saver.hh
@@ -0,0 +1,20 @@
+#pragma once
+
+#include <iostream>
+
+class StateSaver
+{
+public:
+    //! constructor should save all flags and precision
+    StateSaver(std::ostream& os);
+    //! destructor should restore all flags and precision
+    ~StateSaver();
+
+private:
+    //! original stream
+    std::ostream& saved_stream_;
+    //! flags of the original stream
+    std::ios_base::fmtflags saved_flags_;
+    //! precision of the original stream
+    std::streamsize saved_precision_;
+};
diff --git a/graphs/cpp/cartesian_vector/vector.cc b/graphs/cpp/cartesian_vector/vector.cc
new file mode 100644
index 0000000..1291f69
--- /dev/null
+++ b/graphs/cpp/cartesian_vector/vector.cc
@@ -0,0 +1,69 @@
+#include "vector.hh"
+
+#include "state_saver.hh"
+
+Vector::Vector(double x, double y)
+    : x_{ x }
+    , y_{ y }
+{}
+double Vector::get_x() const
+{
+    return x_;
+}
+double Vector::get_y() const
+{
+    return y_;
+}
+Vector& Vector::operator+=(const Vector& rhs)
+{
+    x_ += rhs.get_x();
+    y_ += rhs.get_y();
+    return *this;
+}
+Vector& Vector::operator-=(const Vector& rhs)
+{
+    x_ -= rhs.get_x();
+    y_ -= rhs.get_y();
+    return *this;
+}
+Vector& Vector::operator*=(double scalar)
+{
+    x_ *= scalar;
+    y_ *= scalar;
+    return *this;
+}
+Vector operator+(const Vector& lhs, const Vector& rhs)
+{
+    Vector lhs1{ lhs };
+    return lhs1 += rhs;
+}
+Vector operator-(const Vector& lhs, const Vector& rhs)
+{
+    Vector lhs1{ lhs };
+    return lhs1 -= rhs;
+}
+Vector operator*(const Vector& lhs, double scalar)
+{
+    Vector lhs1{ lhs };
+    return lhs1 *= scalar;
+}
+Vector operator*(double scalar, const Vector& rhs)
+{
+    return rhs * scalar;
+}
+double operator*(const Vector& lhs, const Vector& rhs)
+{
+    return lhs.get_x() * rhs.get_x() + lhs.get_y() * rhs.get_y();
+}
+
+FormatNumericalData Vector::format_numerical_data_{ "[ ", " ]", 12, true,
+                                                    true };
+
+std::ostream& operator<<(std::ostream& os, const Vector& vec)
+{
+    StateSaver savestate{ os };
+    Vector::format_numerical_data_.formatOs(os);
+    os << Vector::format_numerical_data_.prefix << vec.get_x() << " , "
+       << vec.get_y() << Vector::format_numerical_data_.suffix;
+    return os;
+}
+\ No newline at end of file
diff --git a/graphs/cpp/cartesian_vector/vector.hh b/graphs/cpp/cartesian_vector/vector.hh
new file mode 100644
index 0000000..b18838c
--- /dev/null
+++ b/graphs/cpp/cartesian_vector/vector.hh
@@ -0,0 +1,29 @@
+#pragma once
+#include <iostream>
+
+#include "format_numerical_data.hh"
+
+class Vector
+{
+public:
+    Vector() = default;
+    Vector(double x, double y);
+    double get_x() const;
+    double get_y() const;
+
+    Vector& operator+=(const Vector& rhs);
+    Vector& operator-=(const Vector& rhs);
+    Vector& operator*=(double scalar);
+
+    friend Vector operator+(const Vector& lhs, const Vector& rhs);
+    friend Vector operator-(const Vector& lhs, const Vector& rhs);
+    friend Vector operator*(const Vector& lhs, double scalar);
+    friend Vector operator*(double scalar, const Vector& rhs);
+    friend double operator*(const Vector& lhs, const Vector& rhs);
+    friend std::ostream& operator<<(std::ostream& os, const Vector& vec);
+
+private:
+    double x_ = 0;
+    double y_ = 0;
+    static FormatNumericalData format_numerical_data_;
+};
diff --git a/graphs/cpp/cartesian_vector/vector_test.cc b/graphs/cpp/cartesian_vector/vector_test.cc
new file mode 100644
index 0000000..d822c9f
--- /dev/null
+++ b/graphs/cpp/cartesian_vector/vector_test.cc
@@ -0,0 +1,27 @@
+#include <cmath>
+#include <iostream>
+
+#include "vector.hh"
+
+double pi()
+{
+    return std::atan2(0., -1.);
+}
+
+int main()
+{
+    std::cout << "default state pi (double) : " << pi() << '\n';
+    Vector piVector{ pi(), pi() };
+    Vector t(-1.0E-7, 6.812031E-4);
+    std::cout << "piVector :\n" << piVector << '\n';
+    std::cout << "t + piVector :\n" << t + piVector << '\n';
+
+    Vector u{ 1923, 8 };
+    std::cout << "u :\n" << u << '\n';
+    std::cout << "default state (double) : " << u * t << '\n';
+    t -= u;
+    std::cout << "t :\n" << t << '\n';
+    std::cout << "t * 3 :\n" << t * 3 << '\n';
+
+    return 0;
+}