var OBJC_BOOL_IS_BOOL: Int32 { get }
#if OBJC_BOOL_IS_BOOL
//62位iOS、tvOS、watchOS
typedef bool BOOL;
#else
# define OBJC_BOOL_IS_CHAR 1
//32位iOS、macOS
typedef signed char BOOL;
// BOOL is explicitly signed so @encode(BOOL) == "c" rather than "C"
// even if -funsigned-char is used.
#endif
#define YES ((BOOL)1)
#define NO ((BOOL)0)
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sizeof(BOOL) = 1
sizeof(bool) = 1
sizeof(Boolean) = 1
