From df1ef68cd8e8582724ce1192bfc202e0b9aeaf0c Mon Sep 17 00:00:00 2001 From: Karen Arutyunov Date: Tue, 28 Sep 2021 19:24:31 +0300 Subject: Get rid of C++ modules related code and rename *.mxx files to *.hxx --- libbutl/string-table.hxx | 95 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 libbutl/string-table.hxx (limited to 'libbutl/string-table.hxx') diff --git a/libbutl/string-table.hxx b/libbutl/string-table.hxx new file mode 100644 index 0000000..010fb01 --- /dev/null +++ b/libbutl/string-table.hxx @@ -0,0 +1,95 @@ +// file : libbutl/string-table.hxx -*- C++ -*- +// license : MIT; see accompanying LICENSE file + +#pragma once + +#include +#include +#include +#include + +#include + +#include + +namespace butl +{ + // A pool of strings and, optionally, other accompanying data in which each + // entry is assigned an individual index (or id) of type I (e.g., uint8_t, + // uint16_t, etc., depending on how many entries are expected). Index value + // 0 is reserved to indicate the "no entry" condition. + // + template + struct string_table_element + { + const I i; + const D d; + }; + + template + struct string_table_element + { + const I i; + const std::string d; + }; + + // For custom data the options are to call the data member 'key' or to + // specialize this traits. + // + template + struct string_table_traits + { + static const std::string& + key (const D& d) {return d.key;} + }; + + template <> + struct string_table_traits + { + static const std::string& + key (const std::string& d) {return d;} + }; + + template + struct string_table + { + // Insert new entry unless one already exists. + // + I + insert (const D&); + + // Find existing. + // + I + find (const std::string& k) const + { + auto i (map_.find (key_type (&k))); + return i != map_.end () ? i->second.i : 0; + } + + // Reverse lookup. + // + const D& + operator[] (I i) const {assert (i > 0); return vec_[i - 1]->second.d;} + + I + size () const {return static_cast (vec_.size ());} + + bool + empty () const {return vec_.empty ();} + + void + clear () {vec_.clear (); map_.clear ();} + + private: + using key_type = butl::map_key; + using value_type = string_table_element; + using map_type = std::unordered_map; + using traits_type = string_table_traits; + + map_type map_; + std::vector vec_; + }; +} + +#include -- cgit v1.1