Question 1

How much faster is fast_float compared to strtod?

Accepted Answer

fast_float is typically 4-10 times faster, parsing at speeds up to 1 GB/s in benchmarks. It's optimized for high-throughput scenarios like database processing and web browser engines, where performance gains are critical.

Question 2

Can fast_float parse integers in binary or hexadecimal?

Accepted Answer

Yes, it supports parsing integer types with different bases, including binary and hexadecimal, as shown in the README examples. You use the same from_chars function with an optional base parameter for flexible integer conversion.

Question 3

How to parse numbers with a comma as decimal separator in fast_float?

Accepted Answer

Use the from_chars_advanced function with parse_options set to a custom decimal separator like comma. The README provides code snippets for this, allowing locale-dependent parsing while maintaining high performance.

Question 4

Does fast_float support compile-time number parsing in C++20?

Accepted Answer

Yes, it supports constexpr evaluation in C++20, enabling compile-time parsing for scenarios like embedded systems or template metaprogramming where runtime overhead must be minimized.

Question 5

fast_float or fast_double_parser: which should I use?

Accepted Answer

fast_float is generally preferred for its updated algorithm and standard C++ API, with wider adoption in projects like GCC and Chromium. fast_double_parser is older and used in specific frameworks, but fast_float offers better integration and ongoing support.

Question 6

How to handle out-of-range values like 1e1000 in fast_float?

Accepted Answer

By default, it sets the value to infinity or zero and returns std::errc::result_out_of_range. You can override this by checking the error and preserving the original value, as detailed in the README's behavior section.

fast_float

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