76 lines
2.2 KiB
C++
76 lines
2.2 KiB
C++
// Copyright 2020 Dolphin Emulator Project
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// SPDX-License-Identifier: GPL-2.0-or-later
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#pragma once
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#include <cstddef>
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#include <string_view>
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namespace Common
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{
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constexpr std::size_t CountFmtReplacementFields(std::string_view s)
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{
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std::size_t count = 0;
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for (std::size_t i = 0; i < s.size(); ++i)
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{
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if (s[i] != '{')
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continue;
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// If the opening brace is followed by another brace, what we have is
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// an escaped brace, not a replacement field.
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if (i + 1 < s.size() && s[i + 1] == '{')
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{
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// Skip the second brace.
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// This ensures that e.g. {{{}}} is counted correctly: when the first brace character
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// is read and detected as being part of an '{{' escape sequence, the second character
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// is skipped so the most inner brace (the third character) is not detected
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// as the end of an '{{' pair.
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++i;
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continue;
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}
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++count;
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}
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return count;
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}
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static_assert(CountFmtReplacementFields("") == 0);
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static_assert(CountFmtReplacementFields("{} test {:x}") == 2);
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static_assert(CountFmtReplacementFields("{} {{}} test {{{}}}") == 2);
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constexpr bool ContainsNonPositionalArguments(std::string_view s)
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{
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for (std::size_t i = 0; i < s.size(); ++i)
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{
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if (s[i] != '{' || i + 1 == s.size())
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continue;
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const char next = s[i + 1];
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// If the opening brace is followed by another brace, what we have is
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// an escaped brace, not a replacement field.
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if (next == '{')
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{
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// Skip the second brace.
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// This ensures that e.g. {{{}}} is counted correctly: when the first brace character
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// is read and detected as being part of an '{{' escape sequence, the second character
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// is skipped so the most inner brace (the third character) is not detected
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// as the end of an '{{' pair.
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++i;
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}
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else if (next == '}' || next == ':')
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{
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return true;
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}
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}
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return false;
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}
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static_assert(!ContainsNonPositionalArguments(""));
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static_assert(ContainsNonPositionalArguments("{}"));
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static_assert(!ContainsNonPositionalArguments("{0}"));
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static_assert(ContainsNonPositionalArguments("{:x}"));
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static_assert(!ContainsNonPositionalArguments("{0:x}"));
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static_assert(!ContainsNonPositionalArguments("{0} {{}} test {{{1}}}"));
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} // namespace Common
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