nerdcruft/libcruft-util
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io: ensure write/pwrite views use pointer iterators

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This commit is contained in:
Danny Robson 2018-12-19 17:13:06 +11:00
parent fb7c989487
commit 072dce8891
1 changed files with 11 additions and 14 deletions
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25
io.hpp
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@ -9,6 +9,7 @@
#ifndef __UTIL_IO_HPP
#define __UTIL_IO_HPP
#include "std.hpp"
#include "platform.hpp"
#include "posix/fd.hpp"
@ -67,25 +68,23 @@ namespace cruft {
///
/// An exception may be throw in the event forward progress is impossible
/// (depending on the supplied FunctionT).
///
/// TODO: enforce constness of view iterators
template <
typename DstT,
typename FunctionT,
typename IteratorA,
typename IteratorB,
typename ValueT,
typename ...Args
>
[[nodiscard]] decltype(auto)
drain (
DstT &&dst,
FunctionT &&func,
cruft::view<IteratorA,IteratorB> const &src,
cruft::view<ValueT*> const &src,
Args&& ...args
) {
static_assert (std::is_pointer_v<IteratorA>);
static_assert (std::is_pointer_v<IteratorB>);
auto cursor = reinterpret_cast<std::byte const*> (src.data ());
auto remain = src.size ();
auto cursor = reinterpret_cast<u08 const*> (src.data ());
auto remain = src.size () * sizeof (ValueT);
while (remain) {
auto count = std::invoke (func, dst, cursor, remain, args...);
@ -105,11 +104,10 @@ namespace cruft {
/// to `src`.
template <
typename DstT,
typename IteratorA,
typename IteratorB
typename ValueT
>
decltype(auto)
write (DstT &&dst, const cruft::view<IteratorA, IteratorB> &src)
write (DstT &&dst, cruft::view<ValueT*> const &src)
{
constexpr auto func = &std::decay_t<DstT>::write;
return drain (std::forward<DstT> (dst), func, src);
@ -124,11 +122,10 @@ namespace cruft {
/// to `src`.
template <
typename DstT,
typename IteratorA,
typename IteratorB
typename ValueT
>
decltype(auto)
pwrite (DstT &&dst, const cruft::view<IteratorA, IteratorB> &src, size_t offset)
pwrite (DstT &&dst, cruft::view<ValueT*> const &src, size_t offset)
{
return drain (std::forward<DstT> (dst), &std::decay_t<DstT>::pwrite, src, offset);
}