Examples of errors detected by the V709 diagnostic

V709. Suspicious comparison found: 'a == b == c'. Remember that 'a == b == c' is not equal to 'a == b && b == c'.

Unreal Engine 4

V709 Suspicious comparison found: 'a == b == c'. Remember that 'a == b == c' is not equal to 'a == b && b == c'. slatetextures.cpp 67

void FSlateTexture2DRHIRef::InitDynamicRHI()
{
  ....
  checkf(GPixelFormats[PixelFormat].BlockSizeX ==
         GPixelFormats[PixelFormat].BlockSizeY ==
         GPixelFormats[PixelFormat].BlockSizeZ == 1,
         TEXT("Tried to use compressed format?"));
  ....
}

Amazon Lumberyard

V709 CWE-682 Suspicious comparison found: 'a == b == c'. Remember that 'a == b == c' is not equal to 'a == b && b == c'. toglslinstruction.c 564

void CallBinaryOp(....)
{
  ....
  uint32_t src1SwizCount = GetNumSwizzleElements(....);
  uint32_t src0SwizCount = GetNumSwizzleElements(....);
  uint32_t dstSwizCount = GetNumSwizzleElements(....);

  ....
  if (src1SwizCount == src0SwizCount == dstSwizCount) // <=
  {
    ....
  }
  ....
}

Similar errors can be found in some other places:

• V709 CWE-682 Suspicious comparison found: 'a == b == c'. Remember that 'a == b == c' is not equal to 'a == b && b == c'. toglslinstruction.c 654
• V709 CWE-682 Suspicious comparison found: 'a == b == c'. Remember that 'a == b == c' is not equal to 'a == b && b == c'. toglslinstruction.c 469
• V709 CWE-682 Suspicious comparison found: 'a == b == c'. Remember that 'a == b == c' is not equal to 'a == b && b == c'. tometalinstruction.c 539

Bullet Physics SDK

V709 Suspicious comparison found: 'f0 == f1 == m_fractureBodies.size()'. Remember that 'a == b == c' is not equal to 'a == b && b == c'. btFractureDynamicsWorld.cpp 483

btAlignedObjectArray<btFractureBody*> m_fractureBodies;

void btFractureDynamicsWorld::fractureCallback()
{
  for (int i = 0; i < numManifolds; i++)
  {
    ....
    int f0 = m_fractureBodies.findLinearSearch(....);
    int f1 = m_fractureBodies.findLinearSearch(....);

    if (f0 == f1 == m_fractureBodies.size())
      continue;
    ....
  }
....
}