scan_after_whitespace() built the expected text of true, false, and null in
local std::array objects. With -fstack-protector-strong (the default of
Ubuntu's GCC, among others), a local array gives the function a stack canary
check, which then ran on every token. scan_literal() now takes the text
after the first character as a string literal, with its length as a template
parameter; for contiguous input it compares the rest at once and falls back
to the byte loop on a mismatch, so errors are reported at the same
character. It is out of line, which keeps the token dispatch small.
The parser kept the nesting of arrays and objects in a std::vector<bool>,
whose push_back() GCC calls out of line; it is a std::vector<std::uint8_t>
now.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Niels Lohmann
57424ab0b5