45 lines
1.1 KiB
C
45 lines
1.1 KiB
C
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#pragma once
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/* Example:
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int multiplier = 5;
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DECL_LAMBDA(l, int, (int a), {
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return a * multiplier;
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})
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assert(l.func(l.arg, 4) == 20);
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The point of this is to work on both iOS, where GCC inline
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functions don't work, and Linux, where Apple blocks generally
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aren't available.
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*/
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#ifdef __BLOCKS__
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struct _blk {
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void *isa;
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int flags;
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int reserved;
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void *invoke;
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};
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#define LAMBDA_BODY(typ, ret, args, body) \
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({ union { \
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ret (^blk) args; \
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struct _blk *_blk; \
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void *vp; \
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} u = { ^ret args body }; \
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(typ) {u._blk->invoke, u.vp}; \
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})
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#else
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#define LAMBDA_BODY_(typ, ret, args, body) \
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({ ret func args body; \
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(typ) {&func, 0}; \
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})
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#define LAMBDA_BODY(typ, ret, args, body) \
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LAMBDA_BODY_(typ, ret, LAMBDA_UNPAREN args, body)
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#endif
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#define LAMBDA_UNPAREN(args...) (void *_lambda_ignored, ##args)
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#define DECL_LAMBDA(name, ret, args, body) \
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struct { \
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ret (*func) LAMBDA_UNPAREN args; \
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void *arg; \
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} name = LAMBDA_BODY(typeof(name), ret, args, body);
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