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Change number formatting when std::ios_base::fixed is set to print the requested number of digits, padding with zeros as required.

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[SVN r75602]
This commit is contained in:
John Maddock
2011-11-22 09:51:58 +00:00
parent 60525e3a9b
commit 40123e7170
3 changed files with 45 additions and 22 deletions
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8
include/boost/multiprecision/cpp_float.hpp
View File

@@ -1755,6 +1755,14 @@ std::string cpp_float<Digits10>::str(std::streamsize number_of_digits, std::ios_
str.append(1, 'e');
str.append(boost::lexical_cast<std::string>(my_exp));
}
if(showpoint || scientific)
{
std::streamsize chars = str.size() - 1;
BOOST_ASSERT(str.find('.') != std::string::npos); // there must be a decimal point!!
chars = number_of_digits - chars;
if(chars > 0)
str.append(chars, '0');
}
if(isneg())
str.insert(0, 1, '-');
else if(shopos)

27
include/boost/multiprecision/gmp.hpp
View File

@@ -173,17 +173,14 @@ struct gmp_float_imp
void (*free_func_ptr) (void *, size_t);
const char* ps = mpf_get_str (0, &e, 10, static_cast<std::size_t>(digits), m_data);
std::ptrdiff_t sl = std::strlen(ps);
if(ps && *ps == '-')
--sl; // number of digits excluding sign.
result = ps;
if(sl == 0)
{
result = scientific ? "0.0e0" : showpoint ? "0.0" : "0";
if(showpos)
result.insert(0, 1, '+');
return "0";
}
if(*ps == '-')
--sl; // number of digits excluding sign.
result = ps;
if(fixed || (!scientific && (e > -4) && (e <= std::numeric_limits<boost::uintmax_t>::digits10 + 2)))
else if(fixed || (!scientific && (e > -4) && (e <= std::numeric_limits<boost::uintmax_t>::digits10 + 2)))
{
if(1 + e >= sl)
{
@@ -215,8 +212,20 @@ struct gmp_float_imp
if(e)
result += "e" + lexical_cast<std::string>(e);
}
if(shopos && (str[0] != '-'))
str.insert(0, 1, '+');
if(showpoint || scientific)
{
// Pad out end with zeros as required to give required precision.
std::streamsize chars = result.size() - 1;
BOOST_ASSERT(result.find('.') != std::string::npos); // there must be a decimal point!!
BOOST_ASSERT(result.size()); // Better not be a null string by this point!!
if(result[0] == '-')
--chars;
chars = digits - chars;
if(chars > 0)
result.append(static_cast<std::string::size_type>(chars), '0');
}
if(showpos && (result[0] != '-'))
result.insert(0, 1, '+');
mp_get_memory_functions(&alloc_func_ptr, &realloc_func_ptr, &free_func_ptr);
(*free_func_ptr)((void*)ps, std::strlen(ps) + 1);
return result;

32
include/boost/multiprecision/mpfr.hpp
View File

@@ -168,21 +168,15 @@ struct mpfr_float_imp
char* ps = mpfr_get_str (0, &e, 10, static_cast<std::size_t>(digits), m_data, GMP_RNDN);
std::ptrdiff_t sl = std::strlen(ps);
int chars = sl;
if(sl == 0)
{
result = scientific ? "0.0e0" : showpoint ? "0.0" : "0";
if(showpos)
result.insert(0, 1, '+');
return "0";
}
while(ps[chars-1] == '0')
while(chars && (ps[chars-1] == '0'))
--chars;
ps[chars] = 0;
if(*ps == '-')
if(chars && (*ps == '-'))
--chars; // number of digits excluding sign.
if(chars == 0)
return scientific ? "0.0e0" : showpoint ? "0.0" : "0";
result = ps;
result = "0";
else
result = ps;
if(fixed || (!scientific && (e > -4) && (e <= std::numeric_limits<boost::uintmax_t>::digits10 + 2)))
{
if(e >= chars)
@@ -215,8 +209,20 @@ struct mpfr_float_imp
if(e)
result += "e" + lexical_cast<std::string>(e);
}
if(shopos && (str[0] != '-'))
str.insert(0, 1, '+');
if(showpoint || scientific)
{
// Pad out end with zeros as required to give required precision.
std::streamsize chars = result.size() - 1;
BOOST_ASSERT(result.find('.') != std::string::npos); // there must be a decimal point!!
BOOST_ASSERT(result.size()); // Better not be a null string by this point!!
if(result[0] == '-')
--chars;
chars = digits - chars;
if(chars > 0)
result.append(static_cast<std::string::size_type>(chars), '0');
}
if(showpos && (result[0] != '-'))
result.insert(0, 1, '+');
mpfr_free_str(ps);
return result;
}