generalize static_for.h

This commit is contained in:
Christian Zimmermann 2021-04-10 00:58:30 +02:00
parent cf1850923f
commit 48084b2a5e

View file

@ -7,62 +7,51 @@
namespace MultiArrayTools
{
template <size_t BEG, size_t END>
template <size_t BEG, size_t END, size_t OFF>
struct sfor
{
template <typename F>
static void execs(const F& f)
template <typename Incr, typename F, typename Conc>
static inline auto exec(Incr incr, F f, Conc conc)
{
if(BEG < END){
f(std::integral_constant<size_t, BEG>{});
sfor<BEG+1,END>::execs(f);
}
constexpr auto idx = std::integral_constant<size_t, BEG>{};
constexpr auto idxm = std::integral_constant<size_t, BEG+OFF>{};
static_assert(abs(idx.value - END) >= abs(incr(idx) - END),
"this turns out to be a static endless loop");
auto tmp = f(idxm);
return conc(tmp, static_for<incr(idx),END,OFF>::exec(incr,f,conc));
}
template <typename F>
static void execsr(const F& f)
template <typename Incr, typename F, typename Create, typename... Args>
static inline auto unpack(Incr incr, F f, Create create, const Args&... args)
{
if(BEG < END){
f(std::integral_constant<size_t, END-1>{});
sfor<BEG,END-1>::execsr(f);
}
}
template <typename F>
static void exec(const F& f)
{
f(std::integral_constant<size_t, BEG>{});
sfor<BEG+1,END>::exec(f);
}
template <typename F>
static void execr(const F& f)
{
f(std::integral_constant<size_t, END-1>{});
sfor<BEG,END-1>::execr(f);
constexpr auto idx = std::integral_constant<size_t, BEG>{};
constexpr auto idxm = std::integral_constant<size_t, BEG+OFF>{};
static_assert(abs(idx.value - END) >= abs(incr(idx) - END),
"this turns out to be a static endless loop");
auto tmp = f(idxm);
return static_for<incr(idx),END,OFF>::unpack(incr, f, create, args..., tmp);
}
};
template <size_t N>
struct sfor<N,N>
template <size_t END, size_t OFF>
struct sfor<END,END,OFF>
{
template <typename F>
static void execs(const F& f) {}
template <typename Incr, typename F, typename Conc>
static inline auto exec(Incr incr, F f, Conc conc)
{
return 0;
}
template <typename F>
static void execsr(const F& f) {}
template <typename F>
static void exec(const F& f) {}
template <typename F>
static void execr(const F& f) {}
template <typename Incr, typename F, typename Create, typename... Args>
static inline auto unpack(Incr incr, F f, Create create, const Args&... args)
{
return create(args...);
}
};
}
#define MA_SSFOR(i,beg,end,expr) MultiArrayTools::sfor<beg,end>::execs([&](auto i){ expr })
#define MA_SSRFOR(i,end,beg,expr) MultiArrayTools::sfor<beg,end>::execsr([&](auto i){ expr })
#define MA_SFOR(i,beg,end,expr) MultiArrayTools::sfor<beg,end>::exec([&](auto i){ expr })
#define MA_SRFOR(i,end,beg,expr) MultiArrayTools::sfor<beg,end>::execr([&](auto i){ expr })
#define MA_SFOR(i,beg,end,incr,expr) static_for<beg,end,0>::exec([&](auto i) constexpr { return incr; }, [&](auto i){ expr return 0; }, [&](auto f, auto next) { return 0; })
#define MA_SRFOR(i,beg,end,decr,expr) static_for<beg,end,-1>::exec([&](auto i) constexpr { return decr; }, [&](auto i){ expr return 0; }, [&](auto f, auto next) { return 0; })
#define MA_CFOR(i,beg,end,incr,expr,cre) static_for<beg,end,0>::unpack([&](auto i) constexpr { return incr; }, [&](auto i){ expr }, [&](auto... args) { return cre(args...); })
#endif