vector of string to FixedLenStringArray droppoing the last element

[ronzhou]

Describe the bug
When transfering a vector of string to FixedLenStringArray, the last element will get lost.

To Reproduce

std::vector<std::string> x{"abc", "def"};
HighFive::FixedLenStringArray<3> arr(x);
std::cout << x.size() << ":" << arr.size() << std::endl;
assert(x.size() == arr.size() && "size must equal");

[1uc]

I think this is due assumptions about what a string is, precisely. The string literal "abc" is 4 elements long a, b, c and \0. As far as I can tell from looking at the code, e.g.,

HighFive/include/highfive/bits/H5DataType_misc.hpp

Lines 335 to 338 in db6f31e

	const char* src = (iter_begin++)->c_str();
	const size_t length = std::min(N - 1, std::strlen(src));
	std::memcpy(dst_array.data(), src, length);
	dst_array[length] = 0;

HighFive assumes that all strings are null-terminated and enforces this fact. Please try:

HighFive::FixedLenStringArray<4> arr(x);

[1uc]

We're currently working towards supporting strings more cleanly, see #744.

[ronzhou]

@1uc It still raise the size unequal assertion error after change the length from 3 to 4.

[1uc]

You're right, and I didn't read sufficiently carefully. There's a PR that addresses the bug #797. Does it fix the issue?