From 37ff16bbb04881da44bf8f2ef727c526f63004e5 Mon Sep 17 00:00:00 2001 From: Lioncash Date: Wed, 12 Jun 2019 17:47:05 -0400 Subject: [PATCH] common/hex_util: Reserve std::string memory ahead of time Avoids potentially performing multiple reallocations (depending on the size of the input data) by reserving the necessary amount of memory ahead of time. This is trivially doable, so there's no harm in it. --- src/common/hex_util.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/common/hex_util.h b/src/common/hex_util.h index a64c9b4859..bb4736f96f 100644 --- a/src/common/hex_util.h +++ b/src/common/hex_util.h @@ -36,10 +36,15 @@ std::string HexToString(const ContiguousContainer& data, bool upper = true) { static_assert(std::is_same_v, "Underlying type within the contiguous container must be u8."); + constexpr std::size_t pad_width = 2; + std::string out; + out.reserve(std::size(data) * pad_width); + for (const u8 c : data) { out += fmt::format(upper ? "{:02X}" : "{:02x}", c); } + return out; }