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(verify, verify_dcl): New file/macros.
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lib/verify.h
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lib/verify.h
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/* Compile-time assert-like macros.
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Copyright (C) 2005 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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#ifndef VERIFY_H
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# define VERIFY_H 1
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# ifndef verify_dcl
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# define GL_CONCAT0(x, y) x##y
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# define GL_CONCAT(x, y) GL_CONCAT0 (x, y)
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/* Verify requirement, R, at compile-time, as a declaration.
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The implementation uses a struct declaration whose name includes the
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expansion of __LINE__, so there is a small chance that two uses of
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verify_dcl from different files will end up colliding (for example,
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f.c includes f.h and verify_dcl is used on the same line in each). */
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# define verify_dcl(R) \
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struct GL_CONCAT (ct_assert_, __LINE__) { char a[(R) ? 1 : -1]; }
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# endif
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/* Verify requirement, R, at compile-time, as an expression.
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Unlike assert, there is no run-time overhead. Unlike verify_dcl,
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above, there is no risk of collision, since there is no declared name.
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This macro may be used in some contexts where the other may not, and
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vice versa. Return void. */
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# undef verify
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# define verify(R) ((void) sizeof (struct { char a[(R) ? 1 : -1]; }))
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#endif
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