17.4.1.2 Headers [lib.headers]
1)The elements of the C + + Standard Library are declared or defined (as appropriate) in a header.(158)
2)The C + + Standard Library provides 33 C + + headers, as shown in Table 11:
Table 11—C++ Library Headers
_____________________________________
<algorithm> <iomanip> <list> <queue> <streambuf>
<bitset> <ios> <locale> <set> <string>
<complex> <iosfwd> <map> <sstream> <typeinfo>
<deque> <iostream> <memory> <stack> <utility>
<exception> <istream> <new> <stdexcept> <valarray>
<fstream> <iterator> <numeric> <strstream> <vector>
<functional> <limits> <ostream>
____________________________________

3)The facilities of the Standard C Library are provided in 18 additional headers, as shown in Table 12:
Table 12—C + + Headers for C Library Facilities
___________________________________
<cassert> <ciso646> <csetjmp> <cstdio> <ctime>
<cctype> <climits> <csignal> <cstdlib> <cwchar>
<cerrno> <clocale> <cstdarg> <cstring> <cwctype>
<cfloat> <cmath> <cstddef>
__________________________________


4)Except as noted in clauses 18 through 27, the contents of each header cname shall be the same as that of the
corresponding header name.h, as specified in ISO/IEC 9899:1990 Programming Languages C (Clause 7),
or ISO/IEC:1990 Programming Languages—C AMENDMENT 1: C Integrity, (Clause 7), as appropriate,
as if by inclusion. In the C + + Standard Library, however, the declarations and definitions (except for names
which are defined as macros in C) are within namespace scope (3.3.5) of the namespace std.
5) Names which are defined as macros in C shall be defined as macros in the C + + Standard Library, even if C
grants license for implementation as functions. [Note: the names defined as macros in C include the following:
assert, errno, offsetof, setjmp, va_arg, va_end, and va_start. —end note]
A header is not necessarily a source file, nor are the sequences delimited by < and > in header names necessarily valid source file
names (16.2).
ISO/IEC 14882:2003(E) ISO/IEC
17.4.1.2 Headers 17 Library introduction
6)Names that are defined as functions in C shall be defined as functions in the C + + Standard Library.(159)
7)D.5, Standard C library headers, describes the effects of using the name.h (C header) form in a C + + program.


158)A header is not necessarily a source file, nor are the sequences delimited by < and > in header names necessarily valid source file
names (16.2).

159)This disallows the practice, allowed in C, of providing a "masking macro" in addition to the function prototype. The only way to
achieve equivalent "inline" behavior in C + + is to provide a definition as an extern inline function.