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Optimize parse_nonnegative_int
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@ -8,10 +8,10 @@
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#ifndef FMT_CORE_H_
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#define FMT_CORE_H_
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#include <climits> // INT_MAX
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#include <cstdio> // std::FILE
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#include <cstdio> // std::FILE
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#include <cstring>
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#include <iterator>
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#include <limits>
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#include <string>
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#include <type_traits>
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@ -2103,21 +2103,25 @@ template <typename Char, typename ErrorHandler>
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FMT_CONSTEXPR auto parse_nonnegative_int(const Char*& begin, const Char* end,
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ErrorHandler&& eh) -> int {
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FMT_ASSERT(begin != end && '0' <= *begin && *begin <= '9', "");
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unsigned value = 0;
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// Convert to unsigned to prevent a warning.
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const unsigned max_int = to_unsigned(INT_MAX);
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unsigned big = max_int / 10;
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unsigned value = 0, prev = 0;
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auto p = begin;
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do {
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// Check for overflow.
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if (value > big) {
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value = max_int + 1;
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break;
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}
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value = value * 10 + unsigned(*begin - '0');
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++begin;
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} while (begin != end && '0' <= *begin && *begin <= '9');
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if (value > max_int) eh.on_error("number is too big");
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return static_cast<int>(value);
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prev = value;
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value = value * 10 + unsigned(*p - '0');
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++p;
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} while (p != end && '0' <= *p && *p <= '9');
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auto num_digits = p - begin;
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begin = p;
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if (num_digits <= std::numeric_limits<int>::digits10)
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return static_cast<int>(value);
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// Check for overflow.
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const unsigned big = to_unsigned((std::numeric_limits<int>::max)());
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if (num_digits == std::numeric_limits<int>::digits10 + 1 &&
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prev * 10ull + unsigned(p[-1] - '0') <= big) {
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return static_cast<int>(value);
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}
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eh.on_error("number is too big");
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return -1;
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}
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// Parses fill and alignment.
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@ -2454,8 +2458,8 @@ class compile_parse_context
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public:
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explicit FMT_CONSTEXPR compile_parse_context(
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basic_string_view<Char> format_str, int num_args = INT_MAX,
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ErrorHandler eh = {})
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basic_string_view<Char> format_str,
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int num_args = (std::numeric_limits<int>::max)(), ErrorHandler eh = {})
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: base(format_str, eh), num_args_(num_args) {}
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FMT_CONSTEXPR auto next_arg_id() -> int {
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