Check that all indices are valid.

The code tries to make the compiler spit out which one is the
invalid index, if any.
This commit is contained in:
King_DuckZ 2017-07-26 23:31:11 +01:00
parent c1b6bd0500
commit 42f3133640
1 changed files with 34 additions and 1 deletions

View File

@ -41,9 +41,42 @@ namespace vwr {
};
} //namespace op
namespace implem {
//sets value to the index of the first I >= MAX or to sizeof...(I) if
//no such value is found
template <size_type MAX, size_type IDX, size_type... I>
struct find_ge_than_max;
template <size_type MAX, size_type IDX, size_type I>
struct find_ge_than_max<MAX, IDX, I> {
static constexpr size_type value =
IDX + (I >= MAX ? 0 : 1);
};
template <size_type MAX, size_type IDX, size_type L, size_type... I>
struct find_ge_than_max<MAX, IDX, L, I...> {
static constexpr size_type value =
(L >= MAX ? IDX : find_ge_than_max<MAX, IDX + 1, I...>::value);
};
//helper to identify the invalid index in the build error messages
template <size_type INVALID_INDEX, bool INVALID>
struct is_invalid_index {
static_assert(not INVALID,
"Invalid index specified, indices must all be >= 0 and <= dimensions"
);
enum {
value = 0
};
};
} //namespace implem
template <typename V, typename OP, typename CMP, size_type... I>
class sequence_range_iterator : OP, CMP {
//static_assert(VectorWrapperInfo<V>::dimensions >= sizeof...(I), "Start index out of valid range");
static_assert(not implem::is_invalid_index<
implem::find_ge_than_max<V::dimensions, 0, I...>::value,
sizeof...(I) != implem::find_ge_than_max<V::dimensions, 0, I...>::value
>::value, "");
static_assert(sizeof...(I) > 0, "At least one index must be specified");
public:
sequence_range_iterator (const V& parFrom, const V& parUpper);
sequence_range_iterator (const V& parCurrent, const V& parFrom, const V& parUpper);