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slightly less undefined behavior in Vector3D and Vector4D implementation #6

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slightly less undefined behavior in Vector3D and Vector4D implementation #6

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15 changes: 11 additions & 4 deletions CMU462/include/CMU462/vector3D.h
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@

#include <ostream>
#include <cmath>
#include <array>

namespace CMU462 {

Expand All @@ -14,8 +15,14 @@ namespace CMU462 {
class Vector3D {
public:

// components
double x, y, z;
/**
* this type-punning is still technically undefined behavior, but all major
* compilers explicitly define it (gcc, clang, msvc)
*/
union {
struct { double x; double y; double z; };
std::array<double, 3> data;
};

/**
* Constructor.
Expand Down Expand Up @@ -43,12 +50,12 @@ class Vector3D {

// returns reference to the specified component (0-based indexing: x, y, z)
inline double& operator[] ( const int& index ) {
return ( &x )[ index ];
return data[index];
}

// returns const reference to the specified component (0-based indexing: x, y, z)
inline const double& operator[] ( const int& index ) const {
return ( &x )[ index ];
return data[index];
}

inline bool operator==( const Vector3D& v) const {
Expand Down
14 changes: 10 additions & 4 deletions CMU462/include/CMU462/vector4D.h
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Original file line number Diff line number Diff line change
Expand Up @@ -15,8 +15,14 @@ namespace CMU462 {
class Vector4D {
public:

// components
double x, y, z, w;
/**
* this type-punning is still technically undefined behavior, but all major
* compilers explicitly define it (gcc, clang, msvc)
*/
union {
struct { double x; double y; double z; double w; };
std::array<double, 4> data;
};

/**
* Constructor.
Expand Down Expand Up @@ -63,12 +69,12 @@ class Vector4D {

// returns reference to the specified component (0-based indexing: x, y, z)
inline double& operator[] ( const int& index ) {
return ( &x )[ index ];
return data[ index ];
}

// returns const reference to the specified component (0-based indexing: x, y, z)
inline const double& operator[] ( const int& index ) const {
return ( &x )[ index ];
return data[ index ];
}

// negation
Expand Down