etl

058e4c9e - etl/span.h: prevent compound statements in constexpr methods for C++11 (#562)

etl/span.h: prevent compound statements in constexpr methods for C++11 (#562) C++11 doesn't support compound statements in constexpr functions and as a result, `etl/span.h` generates a heap of warnings with gcc's `-Wpedantic` in C++11 mode. This changes the relevant method bodies to contain just a single return statement.