COMPILE_ASSERT

최근에 크롬 코드를 보는데 콤피니엘 이라는 게 발견됐어요.컴파일할 때 판단할 수 있는 ASSERT 매크로COMPILE_ASSERT 매크로의 실현은 D:/project/chrome/src/src/base/basictypes.h, 주석 섹션에는 다음과 같은 원리에 대한 설명이 있습니다.

// The COMPILE_ASSERT macro can be used to verify that a compile time
// expression is true. For example, you could use it to verify the
// size of a static array:
//
//   COMPILE_ASSERT(ARRAYSIZE_UNSAFE(content_type_names) == CONTENT_NUM_TYPES,
//                  content_type_names_incorrect_size);
//
// or to make sure a struct is smaller than a certain size:
//
//   COMPILE_ASSERT(sizeof(foo) < 128, foo_too_large);
//
// The second argument to the macro is the name of the variable. If
// the expression is false, most compilers will issue a warning/error
// containing the name of the variable.

template <bool>
struct CompileAssert {
};

#undef COMPILE_ASSERT
#define COMPILE_ASSERT(expr, msg) /
  typedef CompileAssert<(bool(expr))> msg[bool(expr) ? 1 : -1]

// Implementation details of COMPILE_ASSERT:
//
// - COMPILE_ASSERT works by defining an array type that has -1
//   elements (and thus is invalid) when the expression is false.
//
// - The simpler definition
//
//     #define COMPILE_ASSERT(expr, msg) typedef char msg[(expr) ? 1 : -1]
//
//   does not work, as gcc supports variable-length arrays whose sizes
//   are determined at run-time (this is gcc's extension and not part
//   of the C++ standard).  As a result, gcc fails to reject the
//   following code with the simple definition:
//
//     int foo;
//     COMPILE_ASSERT(foo, msg); // not supposed to compile as foo is
//                               // not a compile-time constant.
//
// - By using the type CompileAssert<(bool(expr))>, we ensures that
//   expr is a compile-time constant.  (Template arguments must be
//   determined at compile-time.)
//
// - The outter parentheses in CompileAssert<(bool(expr))> are necessary
//   to work around a bug in gcc 3.4.4 and 4.0.1.  If we had written
//
//     CompileAssert
    
//
//   instead, these compilers will refuse to compile
//
//     COMPILE_ASSERT(5 > 0, some_message);
//
//   (They seem to think the ">" in "5 > 0" marks the end of the
//   template argument list.)
//
// - The array size is (bool(expr) ? 1 : -1), instead of simply
//
//     ((expr) ? 1 : -1).
//
//   This is to avoid running into a bug in MS VC 7.1, which
//   causes ((0.0) ? 1 : -1) to incorrectly evaluate to 1.

주로 수조의 길이가 0보다 작으면 안 되는 특성을 사용했습니다. 예를 들어 inta[-1]는 컴파일할 때 오류가 발생합니다.각 컴파일러를 호환하기 위해 템플릿 기술을 사용했다.
msdn에서도 COMPILEASSERT:http://blogs.msdn.com/b/abhinaba/archive/2008/10/27/c-c-compile-time-asserts.aspx
boost에서 COMPILE와ASSERT는 BOOST 와 비슷합니다.STATIC_참조할 수 있는 ASSERT:http://www.boost.org/doc/libs/1_36_0/boost/static_assert.hpp
코드를 검색할 때 라이브러리mili(http://code.google.com/p/mili/), 이 안에도 하나의compileassert의 실현(http://code.google.com/p/mili/source/browse/trunk/include/compile_assert.h).이 라이브러리에는 Properties (http://code.google.com/p/mili/wiki/Properties).Properties의 실현 원리는 참고할 수 있다http://xiaolingyao.spaces.live.com/blog/cns!6A8F02D95D2DDE46!201.entry?sa=991256254.