format_sql_to (2 of 2 overloads)

(EXPERIMENTAL) Composes a SQL query client-side appending it to a format context.

void
format_sql_to(
    format_context_base& ctx,
    constant_string_view format_str,
    std::initializer_list< format_arg > args);

Parses format_str as a format string, substituting replacement fields (like {}, {1} or {name}) by formatted arguments, extracted from args.

Formatting is performed as if format_context_base::append_raw and format_context_base::append_value were called on ctx, effectively appending characters to its output string.

Compared to format_sql, this function is more flexible, allowing the following use cases:

Appending characters to an existing context. Can be used to concatenate the output of successive format operations efficiently.
Using string types different to std::string (works with any basic_format_context).
Avoiding exceptions (see basic_format_context::get).

Basic guarantee. Memory allocations may throw.

client_errc::invalid_encoding if args contains a string with byte sequences that can't be decoded with the current character set.
client_errc::unformattable_value if args contains a floating-point value that is NaN or infinity.
Any other error generated by user-defined formatter specializations.
client_errc::format_string_invalid_syntax if format_str can't be parsed as a format string.
client_errc::format_string_invalid_encoding if format_str contains byte byte sequences that can't be decoded with the current character set.
client_errc::format_string_manual_auto_mix if format_str contains a mix of automatic ({}) and manual indexed ({1}) replacement fields.
client_errc::format_arg_not_found if an argument referenced by format_str isn't present in args (there aren't enough arguments or a named argument is not found).

This overload allows using named arguments.

Convenience header <boost/mysql.hpp>

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