21 Language support library [language.support]

21.6 Dynamic memory management [support.dynamic]

21.6.3 Storage allocation errors [alloc.errors]

21.6.3.1 Class bad_­alloc [bad.alloc]

namespace std {
  class bad_alloc : public exception {
  public:
    bad_alloc() noexcept;
    bad_alloc(const bad_alloc&) noexcept;
    bad_alloc& operator=(const bad_alloc&) noexcept;
    const char* what() const noexcept override;
  };
}
The class bad_­alloc defines the type of objects thrown as exceptions by the implementation to report a failure to allocate storage.
bad_alloc() noexcept;
Effects: Constructs an object of class bad_­alloc.
bad_alloc(const bad_alloc&) noexcept; bad_alloc& operator=(const bad_alloc&) noexcept;
Effects: Copies an object of class bad_­alloc.
const char* what() const noexcept override;
Returns: An implementation-defined ntbs.
Remarks: The message may be a null-terminated multibyte string, suitable for conversion and display as a wstring ([string.classes], [locale.codecvt]).