48 lines
1.0 KiB
C++
48 lines
1.0 KiB
C++
#ifndef STAR_LEXICAL_CAST_HPP
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#define STAR_LEXICAL_CAST_HPP
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#include "StarFormat.hpp"
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#include "StarString.hpp"
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#include "StarStringView.hpp"
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#include "StarMaybe.hpp"
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#include <sstream>
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#include <locale>
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namespace Star {
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STAR_EXCEPTION(BadLexicalCast, StarException);
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// Very simple basic lexical cast using stream input. Always operates in the
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// "C" locale.
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template <typename Type>
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Maybe<Type> maybeLexicalCast(StringView s, std::ios_base::fmtflags flags = std::ios_base::boolalpha) {
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Type result;
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std::istringstream stream(std::string(s.utf8()));
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stream.flags(flags);
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stream.imbue(std::locale::classic());
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if (!(stream >> result))
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return {};
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// Confirm that we read everything out of the stream
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char ch;
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if (stream >> ch)
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return {};
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return move(result);
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}
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template <typename Type>
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Type lexicalCast(StringView s, std::ios_base::fmtflags flags = std::ios_base::boolalpha) {
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auto m = maybeLexicalCast<Type>(s, flags);
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if (m)
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return m.take();
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else
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throw BadLexicalCast(strf("Lexical cast failed on '{}'", s));
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}
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}
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#endif
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