concat.h

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/// @file
///
/// Convenience function that concatenates arbitrary arguments, by
/// feeding them to an ostringstream.
 
#ifndef MYSQL_UTILS_CONCAT_H
#define MYSQL_UTILS_CONCAT_H
 
#include <sstream>                       // ostringstream
#include <string>                        // string
#include <utility>                       // ignore
#include "mysql/utils/call_and_catch.h"  // call_and_catch
 
/// @addtogroup GroupLibsMysqlUtils
/// @{
 
namespace mysql::utils::throwing {
 
/// Stream all the arguments to a stringstream and return the resulting string.
///
/// @tparam Args_t types of the arguments.
///
/// @param args Arguments to concatenate.
///
/// @return The resulting std::string.
///
/// @throws bad_alloc if an out-of-memory condition occurs.
template <class... Args_t>
[[nodiscard]] std::string concat(Args_t &&...args) {
  std::ostringstream out;
  // std::ignore required to workaround
  // https://github.com/llvm/llvm-project/issues/140205
  std::ignore = (out << ... << std::forward<Args_t>(args));
  return out.str();
}
 
}  // namespace mysql::utils::throwing
 
namespace mysql::utils {
 
/// Stream all the arguments to a stringstream and return the resulting string.
///
/// @param args Arguments to concatenate.
///
/// @return std::optional<std::string>, holding a value on success, or holding
/// no value if an out-of-memory condition occurs.
template <class... Args_t>
[[nodiscard]] std::optional<std::string> concat(Args_t &&...args) noexcept {
  return call_and_catch(
      [&] { return throwing::concat(std::forward<Args_t>(args)...); });
}
 
}  // namespace mysql::utils
/// @}
 
#endif  // MYSQL_UTILS_CONCAT_H