vtkAssume.h

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/*=========================================================================
 
  Program:   Visualization Toolkit
  Module:    vtkAssume.h
 
  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
 
     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.
 
=========================================================================*/
#ifndef vtkAssume_h
#define vtkAssume_h
 
#include "vtkCompiler.h"
 
#include <cassert>
 
#define VTK_ASSUME(cond)                                                                           \
  do                                                                                               \
  {                                                                                                \
    const bool c = cond;                                                                           \
    assert("Bad assumption in VTK_ASSUME: " #cond&& c);                                            \
    VTK_ASSUME_IMPL(c);                                                                            \
    (void)c;      /* Prevents unused var warnings */                                               \
  } while (false) /* do-while prevents extra semicolon warnings */
 
#define VTK_ASSUME_NO_ASSERT(cond)                                                                 \
  do                                                                                               \
  {                                                                                                \
    const bool c = cond;                                                                           \
    VTK_ASSUME_IMPL(c);                                                                            \
    (void)c;      /* Prevents unused var warnings */                                               \
  } while (false) /* do-while prevents extra semicolon warnings */
 
// VTK_ASSUME_IMPL is compiler-specific:
#if defined(VTK_COMPILER_MSVC) || defined(VTK_COMPILER_ICC)
#define VTK_ASSUME_IMPL(cond) __assume(cond)
#elif defined(VTK_COMPILER_GCC) || defined(VTK_COMPILER_CLANG)
#define VTK_ASSUME_IMPL(cond)                                                                      \
  if (!(cond))                                                                                     \
  __builtin_unreachable()
#else
#define VTK_ASSUME_IMPL(cond)                                                                      \
  do                                                                                               \
  {                                                                                                \
  } while (false) /* no-op */
#endif
 
#endif // vtkAssume_h
// VTK-HeaderTest-Exclude: vtkAssume.h