From f216c76c56cdffb5214d074a7d44812843dd174f Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Mon, 26 Nov 2018 19:57:20 +0100 Subject: [PATCH] Bindings::get(): Add convenience method This allows writing attribute lookups as if (auto name = value.attrs->get(state.sName)) ... --- configure.ac | 2 +- src/libexpr/attr-set.hh | 9 +++++++++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/configure.ac b/configure.ac index 5a2526672..b550231cb 100644 --- a/configure.ac +++ b/configure.ac @@ -62,7 +62,7 @@ CXXFLAGS= AC_PROG_CC AC_PROG_CXX AC_PROG_CPP -AX_CXX_COMPILE_STDCXX_14 +AX_CXX_COMPILE_STDCXX_17 # Use 64-bit file system calls so that we can support files > 2 GiB. diff --git a/src/libexpr/attr-set.hh b/src/libexpr/attr-set.hh index 3119a1848..6c5fb21ad 100644 --- a/src/libexpr/attr-set.hh +++ b/src/libexpr/attr-set.hh @@ -4,6 +4,7 @@ #include "symbol-table.hh" #include +#include namespace nix { @@ -63,6 +64,14 @@ public: return end(); } + std::optional get(const Symbol & name) + { + Attr key(name, 0); + iterator i = std::lower_bound(begin(), end(), key); + if (i != end() && i->name == name) return &*i; + return {}; + } + iterator begin() { return &attrs[0]; } iterator end() { return &attrs[size_]; }