{

constexpr double d = DBL_MIN;

// for scientific, precision + 7 should suffice:

// <digit> <.> <#precision digits> <e> <sign> <up to 3 digits>

// 1 2 3 4 7

constexpr size_t buf_size = precision + 7;

char buf[buf_size];

auto result = boost::charconv::to_chars(buf, buf + buf_size, d, boost::charconv::chars_format::scientific, precision);

BOOST_TEST(result);

// We have to use memcmp here since there is no space to null terminate

BOOST_TEST(std::memcmp(buf, result_string, precision) == 0);

{

constexpr double d = -DBL_MIN;

// for scientific, precision + 7 should suffice:

// <digit> <.> <#precision digits> <e> <sign> <up to 3 digits>

// 1 2 3 4 7

constexpr size_t buf_size = 1 + precision + 7;

char buf[buf_size];

auto result = boost::charconv::to_chars(buf, buf + buf_size, d, boost::charconv::chars_format::scientific, precision);

BOOST_TEST(result);

// We have to use memcmp here since there is no space to null terminate

BOOST_TEST(std::memcmp(buf, result_string, precision) == 0);

{

// DBL_MIN = 2.2250738585072013830902327173324040642192159804623318306e-308

test<1>("2.2e-308");

test<2>("2.23e-308");

test<3>("2.225e-308");

test<4>("2.2251e-308");

test<5>("2.22507e-308");

test_negative<1>("-2.2e-308");

test_negative<2>("-2.23e-308");

test_negative<3>("-2.225e-308");

test_negative<4>("-2.2251e-308");

test_negative<5>("-2.22507e-308");

return boost::report_errors();