// balcl_constraint.h                                                 -*-C++-*-
#ifndef INCLUDED_BALCL_CONSTRAINT
#define INCLUDED_BALCL_CONSTRAINT

#include <bsls_ident.h>
BSLS_IDENT("$Id: $")

//@PURPOSE: Define constraint function signatures for supported value types.
//
//@CLASSES:
//   balcl::Constraint: constraint function signatures for supported types
//
//@DESCRIPTION: This component defines a single `struct`, `balcl::Constraint`,
// that provides a namespace for function signatures used to impose
// user-defined constraints on values entered with command-line options (if so
// defined).  Signatures are defined for each of the supported
// command-line-option values of scalar type.
//
// For further details see [](balcl_commandline#Type-and-Constraint Field) and
// [](balcl_commandline#Example: Type-and-Constraint Field).
//
///Usage
///-----
// The intended use of this component is illustrated in
// [](balcl_commandline#Usage).

#include <balscm_version.h>

#include <bsls_types.h>     // 'bsls::Types::Int64'

#include <bsl_functional.h> // 'bsl::function'
#include <bsl_iosfwd.h>
#include <bsl_string.h>

#include <bdlt_date.h>
#include <bdlt_datetime.h>
#include <bdlt_time.h>

namespace BloombergLP {


namespace balcl {
                        // =================
                        // struct Constraint
                        // =================

/// This `struct` provides a namespace that defines the types used to impose
/// user-defined constraints on values associated with command-line options.
/// One type is defined for each scalar type defined in `balcl::OptionType`
/// except for `bool`.
struct Constraint {

    // TYPES
    typedef bsl::function<bool(const char               *,
                               bsl::ostream&             )> CharConstraint;
    typedef bsl::function<bool(const int                *,
                               bsl::ostream&             )> IntConstraint;
    typedef bsl::function<bool(const bsls::Types::Int64 *,
                               bsl::ostream&             )> Int64Constraint;
    typedef bsl::function<bool(const double             *,
                               bsl::ostream&             )> DoubleConstraint;
    typedef bsl::function<bool(const bsl::string        *,
                               bsl::ostream&             )> StringConstraint;
    typedef bsl::function<bool(const bdlt::Datetime     *,
                               bsl::ostream&             )> DatetimeConstraint;
    typedef bsl::function<bool(const bdlt::Date         *,
                               bsl::ostream&             )> DateConstraint;

    /// These types are aliases for function objects (functors) used to
    /// express user-defined constraints on option values.  Such objects
    /// should return `true` if the supplied value (first argument) are
    /// deemed valid, and `false` otherwise.  Descriptive error messages may
    /// be written to the supplied stream (second argument).
    typedef bsl::function<bool(const bdlt::Time         *,
                               bsl::ostream&             )> TimeConstraint;
};

}  // close package namespace
}  // close enterprise namespace

#endif

// ----------------------------------------------------------------------------
// Copyright 2020 Bloomberg Finance L.P.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ----------------------------- END-OF-FILE ----------------------------------
