From 79a20f96a565119a0a25dddfd7a1499962a4c800 Mon Sep 17 00:00:00 2001 From: fanquake Date: Tue, 27 Jun 2023 12:49:29 +0100 Subject: [PATCH] Merge bitcoin/bitcoin#27929: Added static_assert to check that base_blob is using whole bytes. 5fc4939e17509534eb36727b27ac0afb941e44f7 Added static_assert to check that base_blob is using whole bytes. (Brotcrunsher) Pull request description: Prior to this commit it was possible to create base_blobs with any arbitrary amount of bits, like base_blob<9>. One could assume that this would be a valid way to create a bit field that guarantees to have at least 9 bits. However, in such a case, base_blob would not behave as expected because the WIDTH is rounded down to the closest whole byte (simple integer division by 8). This commit makes sure that this oddity is detected and blocked by the compiler. ACKs for top commit: MarcoFalke: lgtm ACK 5fc4939e17509534eb36727b27ac0afb941e44f7 theStack: ACK 5fc4939e17509534eb36727b27ac0afb941e44f7 stickies-v: ACK 5fc4939e17509534eb36727b27ac0afb941e44f7 Tree-SHA512: 6a06760f09d4a9e6f0b9338d4dddd4091f2ac59a843a443d9302959936d72c55f7cccd55a51ec3a5a799921f68be1b87968ef3c9c11d3389cbd369b5045bb50a --- src/uint256.h | 1 + 1 file changed, 1 insertion(+) diff --git a/src/uint256.h b/src/uint256.h index eb0e9836d6..0106cd5114 100644 --- a/src/uint256.h +++ b/src/uint256.h @@ -23,6 +23,7 @@ class base_blob { protected: static constexpr int WIDTH = BITS / 8; + static_assert(BITS % 8 == 0, "base_blob currently only supports whole bytes."); std::array m_data; static_assert(WIDTH == sizeof(m_data), "Sanity check");