Boost.Any is a C++ library that offers a safe, generic container for single values of different value types.
Boost.Any is a C++ library that offers a safe, generic container for single values of different value types.
Questions tagged [boost-any]
118 questions
1
vote
2 answers
Different key type in a map
for a particular requirement I want to have a map with keys in different type. Similar to boost:any. (I have an old gcc version)
map aMap;
//in runtime :
aMap[1] = "aaa";
aMap["myKey"] = "bbb";
is this something possible with the…
user3291059
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0 answers
variable return type in function that returns held object of boost::any
Say I have a class C with a field of type std::vector. I have index operator const boost::any C::operator[](const size_t i); but what if I wanted C::operator[](const size_t i) to return the object held by the any object at index i rather…
lo tolmencre
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1 answer
Why don't the any_cast function overloads cause ambiguity?
Boost's has:
template
ValueType any_cast(any & operand);
template
inline ValueType any_cast(const any & operand);
(among other variants.) Shouldn't this combination cause ambiguity in calls…
einpoklum
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0 answers
Helper Function to extract values from boost::variant inside a boost::any
I'm using different boost::variant types throughout my projects. For example I have
typedef boost::variant TA;
typedef boost::variant TB;
typedef boost::variant TC;
In order to transport these different boost::variant…
Aleph0
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1 answer
Does std::any employ type erasure, sub-typing, or polymorphism?
While reading the documentation on boost any and experimental any,
I did not see any mention of type erasure.
I'm trying to understand the concept of "type erasure" as it applies to C++.
Is it correct to say that the "any" type uses "type…
Trevor Hickey
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2 answers
boost::any, variants, calling functions based on arrays of them
Given a set of functions, such as:
template
Void Go(A1 a);
template
Void Go(A1 a1, A2 a2);
template
Void Go(A1 a1, A2 a2, A3 a3);
Is it possible to take an array of some variant type and…
Robinson
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boost::any constructors - const type overload resolution
boost::any has a perfect forward constructor declared as:
template
any(ValueType&& value
, typename boost::disable_if >::type* = 0 // disable if value has type `any&`
, typename…
tukra
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1 answer
How to print a vector of boost::any, when i have the element types stored in another vector of strings?
I'm using a vector of boost::any to store different data types, to construct a symbol table from a given program file.
I'm also storing their datatypes in a separate vector as strings.
while trying to print the boost::any using…
Tauseef
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1 answer
Type un-erasure from a boost::program_options value
I'm trying to retrofit my program with boost::program_options. Among other things, I've written a function which I just can't get to compile. Here's a sort-of-minimal .cpp file which fails compilation:
#include
template…
einpoklum
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1 answer
template copy constructor in boost::any
template copy constructor in boost::any
I am confused with these codes in any.hpp of boost.
template
any(const ValueType & value)
: content(new holder<
BOOST_DEDUCED_TYPENAME…
izual
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1 answer
How to get a const reference to data held by boost::any?
I am having trouble maintaining const correctness after trying to retrieve a boost::any instance through boost::any_cast reference casting.
My code:
MyMap paramMapToSet;
MyMap& paramMap = ¶mMapToSet;
const MyMap& constParamMap =…
MatrixAndrew
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1 answer
Storing objects in the array
I want to save boost signals objects in the map (association: signal name → signal object). The signals signature is different, so the second type of map should be boost::any.
map mSignalAssociation;
The question is how to store…
Max Frai
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1 answer
Polymorphism, variadic template inheritance, slicing, boost::any type cast
This program compiles, but the boost::any cast fails. I suspect that slicing a template class this way confuses pointer arithmetic. The idea is that what is stored in the container
std::vector pressures;
are of different types, for…
Ivan
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1 answer
Trying to learn BOOST::ANY Q1
This program segfaults on the call
p->Change(1999);
When I run it in the debugger, it appears that I enter the Change function, but on inspecting the this pointer is 0x00. I am obviously using BOOST::any incorrectly, but I am not sure what I am…
Ivan
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Boost::any assign string value
IDE - Clion, C++11,
Boost Version 1.57.0
Why doesn't work this code?
#include "boost/any.hpp"
...
boost::any var = 1550; // Works
var = "String"; // Error
But works fine this one:
#include "boost/any.hpp"
...
boost::any var = 1550; //…
Person.Junkie
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