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string2Int(): Return std::optional

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This commit is contained in:
Eelco Dolstra 2021-01-08 12:22:21 +01:00
parent 29a445840a
commit 6548b89cc4
17 changed files with 82 additions and 69 deletions
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4
src/libutil/args.hh
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@ -87,7 +87,9 @@ protected:
template<class I>
Handler(I * dest)
: fun([=](std::vector<std::string> ss) {
if (!string2Int(ss[0], *dest))
if (auto n = string2Int<I>(ss[0]))
*dest = *n;
else
throw UsageError("'%s' is not an integer", ss[0]);
})
, arity(1)

4
src/libutil/config.cc
View file

@ -230,7 +230,9 @@ template<typename T>
void BaseSetting<T>::set(const std::string & str, bool append)
{
static_assert(std::is_integral<T>::value, "Integer required.");
if (!string2Int(str, value))
if (auto n = string2Int<T>(str))
value = *n;
else
throw UsageError("setting '%s' has invalid value '%s'", name, str);
}

18
src/libutil/util.hh
View file

@ -397,21 +397,27 @@ bool statusOk(int status);
/* Parse a string into an integer. */
template<class N> bool string2Int(const string & s, N & n)
template<class N>
std::optional<N> string2Int(const std::string & s)
{
if (string(s, 0, 1) == "-" && !std::numeric_limits<N>::is_signed)
return false;
if (s.substr(0, 1) == "-" && !std::numeric_limits<N>::is_signed)
return {};
std::istringstream str(s);
N n;
str >> n;
return str && str.get() == EOF;
if (str && str.get() == EOF) return n;
return {};
}
/* Parse a string into a float. */
template<class N> bool string2Float(const string & s, N & n)
template<class N>
std::optional<N> string2Float(const string & s)
{
std::istringstream str(s);
N n;
str >> n;
return str && str.get() == EOF;
if (str && str.get() == EOF) return n;
return {};
}