Fix -Wshorten-64-to-32 warning on Android NDK when targeting x86 #604
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stat.h defines struct stat to use long long on Android NDK when targeting x86; off_t however is defined as long, which is 32-bit (unlike other Unix-like platforms). This results in a narrowing conversion which produces a warning, and can also result in silently reading a prefix of a huge file instead of a clean "out of memory" error. There's no way for us to preserve the type exactly but always widening to long long should be safe; get_file_size will proceed to check if length actually fits into size_t which is what we ultimately need, and that overflow check will fail on files that are >4 GB in size.
…nction Since there's no reasonable way for us to figure out what the type of stat::st_size is on Android NDK without resorting to C++11 auto / non-standard decltype extensions, we're going to resort to a templated function that can deduce the length type. The rest of the validation and conversion logic is preserved as is.
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stat.h defines struct stat to use long long on Android NDK when targeting x86; off_t however is defined as long, which is 32-bit (unlike other Unix-like platforms). This results in a narrowing conversion which produces a warning, and can also result in silently reading a prefix of a huge file instead of a clean "out of memory" error. To avoid this, we need to deduce the type of stat::st_size which requires moving the length conversion logic to a templated function since we can't use
auto/decltypebefore C++11.Fixes #603.