std::istream::get的误用

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今天想从流里面读数据到内存块里，写出如下代码：pStream->get(ba.data(), nCount)，结果发现内存块里的数据错误，从某个字节以后都未赋值。仔细阅读了get函数的说明，明白错误出在了下面的第2条上。因为我读取的数据里有一个回车字符，用get函数会导致它自动截断。如果要从一个流读取内存块，正确的做法是用read方法。

std::istream::get

single character (1)	int get(); istream& get (char& c);
c-string (2)	istream& get (char* s, streamsize n); istream& get (char* s, streamsize n, char delim);
stream buffer (3)	istream& get (streambuf& sb); istream& get (streambuf& sb, char delim);

Get characters

Extracts characters from the stream, as unformatted input:

(1) single character

Extracts a single character from the stream.
The character is either returned (first signature), or set as the value of its argument (second signature).

(2) c-string

Extracts characters from the stream and stores them in s as a c-string, until either (n-1) characters have been extracted or the delimiting character is encountered: the delimiting character being either the newline character ( '\n') or delim (if this argument is specified).
The delimiting character is not extracted from the input sequence if found, and remains there as the next character to be extracted from the stream (see getline for an alternative that does discard the delimiting character).
A null character ( '\0') is automatically appended to the written sequence if n is greater than zero, even if an empty string is extracted.

(3) stream buffer

Extracts characters from the stream and inserts them into the output sequence controlled by the stream buffer object sb, stopping either as soon as such an insertion fails or as soon as the delimiting character is encountered in the input sequence (the delimiting character being either the newline character, '\n', or delim, if this argument is specified).
Only the characters successfully inserted into sb are extracted from the stream: Neither the delimiting character, nor eventually the character that failed to be inserted at sb, are extracted from the input sequence and remain there as the next character to be extracted from the stream.