Bench log

Not reusing format buffer edea27a

test bench::empty_log_discard     ... bench:          54 ns/iter (+/- 0)
test bench::empty_logger_clone    ... bench:          10 ns/iter (+/- 0)
test bench::empty_logger_new      ... bench:          44 ns/iter (+/- 0)
test bench::nonempty_log_discard  ... bench:          65 ns/iter (+/- 1)
test bench::nonempty_logger_clone ... bench:          10 ns/iter (+/- 0)
test bench::nonempty_logger_new   ... bench:         142 ns/iter (+/- 0)

Reusing format buffer ff4b78d

test bench::empty_log_discard     ... bench:          55 ns/iter (+/- 0)
test bench::empty_logger_clone    ... bench:          25 ns/iter (+/- 1)
test bench::empty_logger_new      ... bench:          37 ns/iter (+/- 0)
test bench::nonempty_log_discard  ... bench:          66 ns/iter (+/- 0)
test bench::nonempty_logger_clone ... bench:          56 ns/iter (+/- 0)
test bench::nonempty_logger_new   ... bench:         121 ns/iter (+/- 1)

TL format buffer 43929c2

test bench::empty_log_discard     ... bench:          56 ns/iter (+/- 1)
test bench::empty_logger_clone    ... bench:          21 ns/iter (+/- 0)
test bench::empty_logger_new      ... bench:          25 ns/iter (+/- 0)
test bench::nonempty_log_discard  ... bench:          68 ns/iter (+/- 1)
test bench::nonempty_logger_clone ... bench:          51 ns/iter (+/- 0)
test bench::nonempty_logger_new   ... bench:         107 ns/iter (+/- 1)

Lazy ts in RecordInfo - aab82a2

test bench::empty_log_discard     ... bench:          28 ns/iter (+/- 0)
test bench::empty_logger_clone    ... bench:          21 ns/iter (+/- 6)
test bench::empty_logger_new      ... bench:          25 ns/iter (+/- 0)
test bench::nonempty_log_discard  ... bench:          39 ns/iter (+/- 0)
test bench::nonempty_logger_clone ... bench:          52 ns/iter (+/- 3)
test bench::nonempty_logger_new   ... bench:         107 ns/iter (+/- 1)

&'a str in RecordInfo (in progress)

test bench::empty_log_discard     ... bench:          26 ns/iter (+/- 0)
test bench::empty_logger_clone    ... bench:          21 ns/iter (+/- 0)
test bench::empty_logger_new      ... bench:          25 ns/iter (+/- 0)
test bench::nonempty_log_discard  ... bench:          26 ns/iter (+/- 0)
test bench::nonempty_logger_clone ... bench:          51 ns/iter (+/- 0)
test bench::nonempty_logger_new   ... bench:         107 ns/iter (+/- 0)